src/share/vm/opto/escape.cpp

Fri, 10 Feb 2012 12:53:43 -0800

author
kvn
date
Fri, 10 Feb 2012 12:53:43 -0800
changeset 3564
73df3733f2eb
parent 3406
e9a5e0a812c8
child 3604
9a72c7ece7fb
permissions
-rw-r--r--

7129284: +DoEscapeAnalysis regression w/ early build of 7u4 (HotSpot 23) on Linux
Summary: Removed code which tried to create edges from fields of destination objects of arraycopy to fields of source objects. Added 30 sec time limit for EA graph construction.
Reviewed-by: never

     1 /*
     2  * Copyright (c) 2005, 2012, 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   _pcmp_neq = NULL; // Should be initialized
   123   _pcmp_eq  = NULL;
   124 }
   126 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
   127   PointsToNode *f = ptnode_adr(from_i);
   128   PointsToNode *t = ptnode_adr(to_i);
   130   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   131   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
   132   assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
   133   if (to_i == _phantom_object) { // Quick test for most common object
   134     if (f->has_unknown_ptr()) {
   135       return;
   136     } else {
   137       f->set_has_unknown_ptr();
   138     }
   139   }
   140   add_edge(f, to_i, PointsToNode::PointsToEdge);
   141 }
   143 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
   144   PointsToNode *f = ptnode_adr(from_i);
   145   PointsToNode *t = ptnode_adr(to_i);
   147   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   148   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
   149   assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
   150   // don't add a self-referential edge, this can occur during removal of
   151   // deferred edges
   152   if (from_i != to_i)
   153     add_edge(f, to_i, PointsToNode::DeferredEdge);
   154 }
   156 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
   157   const Type *adr_type = phase->type(adr);
   158   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
   159       adr->in(AddPNode::Address)->is_Proj() &&
   160       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
   161     // We are computing a raw address for a store captured by an Initialize
   162     // compute an appropriate address type. AddP cases #3 and #5 (see below).
   163     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
   164     assert(offs != Type::OffsetBot ||
   165            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
   166            "offset must be a constant or it is initialization of array");
   167     return offs;
   168   }
   169   const TypePtr *t_ptr = adr_type->isa_ptr();
   170   assert(t_ptr != NULL, "must be a pointer type");
   171   return t_ptr->offset();
   172 }
   174 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
   175   // Don't add fields to NULL pointer.
   176   if (is_null_ptr(from_i))
   177     return;
   178   PointsToNode *f = ptnode_adr(from_i);
   179   PointsToNode *t = ptnode_adr(to_i);
   181   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   182   assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
   183   assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
   184   assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
   185   t->set_offset(offset);
   187   add_edge(f, to_i, PointsToNode::FieldEdge);
   188 }
   190 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
   191   // Don't change non-escaping state of NULL pointer.
   192   if (is_null_ptr(ni))
   193     return;
   194   PointsToNode *npt = ptnode_adr(ni);
   195   PointsToNode::EscapeState old_es = npt->escape_state();
   196   if (es > old_es)
   197     npt->set_escape_state(es);
   198 }
   200 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
   201                                PointsToNode::EscapeState es, bool done) {
   202   PointsToNode* ptadr = ptnode_adr(n->_idx);
   203   ptadr->_node = n;
   204   ptadr->set_node_type(nt);
   206   // inline set_escape_state(idx, es);
   207   PointsToNode::EscapeState old_es = ptadr->escape_state();
   208   if (es > old_es)
   209     ptadr->set_escape_state(es);
   211   if (done)
   212     _processed.set(n->_idx);
   213 }
   215 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
   216   uint idx = n->_idx;
   217   PointsToNode::EscapeState es;
   219   // If we are still collecting or there were no non-escaping allocations
   220   // we don't know the answer yet
   221   if (_collecting)
   222     return PointsToNode::UnknownEscape;
   224   // if the node was created after the escape computation, return
   225   // UnknownEscape
   226   if (idx >= nodes_size())
   227     return PointsToNode::UnknownEscape;
   229   es = ptnode_adr(idx)->escape_state();
   231   // if we have already computed a value, return it
   232   if (es != PointsToNode::UnknownEscape &&
   233       ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
   234     return es;
   236   // PointsTo() calls n->uncast() which can return a new ideal node.
   237   if (n->uncast()->_idx >= nodes_size())
   238     return PointsToNode::UnknownEscape;
   240   PointsToNode::EscapeState orig_es = es;
   242   // compute max escape state of anything this node could point to
   243   for(VectorSetI i(PointsTo(n)); i.test() && es != PointsToNode::GlobalEscape; ++i) {
   244     uint pt = i.elem;
   245     PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
   246     if (pes > es)
   247       es = pes;
   248   }
   249   if (orig_es != es) {
   250     // cache the computed escape state
   251     assert(es > orig_es, "should have computed an escape state");
   252     set_escape_state(idx, es);
   253   } // orig_es could be PointsToNode::UnknownEscape
   254   return es;
   255 }
   257 VectorSet* ConnectionGraph::PointsTo(Node * n) {
   258   pt_ptset.Reset();
   259   pt_visited.Reset();
   260   pt_worklist.clear();
   262 #ifdef ASSERT
   263   Node *orig_n = n;
   264 #endif
   266   n = n->uncast();
   267   PointsToNode* npt = ptnode_adr(n->_idx);
   269   // If we have a JavaObject, return just that object
   270   if (npt->node_type() == PointsToNode::JavaObject) {
   271     pt_ptset.set(n->_idx);
   272     return &pt_ptset;
   273   }
   274 #ifdef ASSERT
   275   if (npt->_node == NULL) {
   276     if (orig_n != n)
   277       orig_n->dump();
   278     n->dump();
   279     assert(npt->_node != NULL, "unregistered node");
   280   }
   281 #endif
   282   pt_worklist.push(n->_idx);
   283   while(pt_worklist.length() > 0) {
   284     int ni = pt_worklist.pop();
   285     if (pt_visited.test_set(ni))
   286       continue;
   288     PointsToNode* pn = ptnode_adr(ni);
   289     // ensure that all inputs of a Phi have been processed
   290     assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
   292     int edges_processed = 0;
   293     uint e_cnt = pn->edge_count();
   294     for (uint e = 0; e < e_cnt; e++) {
   295       uint etgt = pn->edge_target(e);
   296       PointsToNode::EdgeType et = pn->edge_type(e);
   297       if (et == PointsToNode::PointsToEdge) {
   298         pt_ptset.set(etgt);
   299         edges_processed++;
   300       } else if (et == PointsToNode::DeferredEdge) {
   301         pt_worklist.push(etgt);
   302         edges_processed++;
   303       } else {
   304         assert(false,"neither PointsToEdge or DeferredEdge");
   305       }
   306     }
   307     if (edges_processed == 0) {
   308       // no deferred or pointsto edges found.  Assume the value was set
   309       // outside this method.  Add the phantom object to the pointsto set.
   310       pt_ptset.set(_phantom_object);
   311     }
   312   }
   313   return &pt_ptset;
   314 }
   316 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
   317   // This method is most expensive during ConnectionGraph construction.
   318   // Reuse vectorSet and an additional growable array for deferred edges.
   319   deferred_edges->clear();
   320   visited->Reset();
   322   visited->set(ni);
   323   PointsToNode *ptn = ptnode_adr(ni);
   324   assert(ptn->node_type() == PointsToNode::LocalVar ||
   325          ptn->node_type() == PointsToNode::Field, "sanity");
   326   assert(ptn->edge_count() != 0, "should have at least phantom_object");
   328   // Mark current edges as visited and move deferred edges to separate array.
   329   for (uint i = 0; i < ptn->edge_count(); ) {
   330     uint t = ptn->edge_target(i);
   331 #ifdef ASSERT
   332     assert(!visited->test_set(t), "expecting no duplications");
   333 #else
   334     visited->set(t);
   335 #endif
   336     if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
   337       ptn->remove_edge(t, PointsToNode::DeferredEdge);
   338       deferred_edges->append(t);
   339     } else {
   340       i++;
   341     }
   342   }
   343   for (int next = 0; next < deferred_edges->length(); ++next) {
   344     uint t = deferred_edges->at(next);
   345     PointsToNode *ptt = ptnode_adr(t);
   346     uint e_cnt = ptt->edge_count();
   347     assert(e_cnt != 0, "should have at least phantom_object");
   348     for (uint e = 0; e < e_cnt; e++) {
   349       uint etgt = ptt->edge_target(e);
   350       if (visited->test_set(etgt))
   351         continue;
   353       PointsToNode::EdgeType et = ptt->edge_type(e);
   354       if (et == PointsToNode::PointsToEdge) {
   355         add_pointsto_edge(ni, etgt);
   356       } else if (et == PointsToNode::DeferredEdge) {
   357         deferred_edges->append(etgt);
   358       } else {
   359         assert(false,"invalid connection graph");
   360       }
   361     }
   362   }
   363   if (ptn->edge_count() == 0) {
   364     // No pointsto edges found after deferred edges are removed.
   365     // For example, in the next case where call is replaced
   366     // with uncommon trap and as result array's load references
   367     // itself through deferred edges:
   368     //
   369     // A a = b[i];
   370     // if (c!=null) a = c.foo();
   371     // b[i] = a;
   372     //
   373     // Assume the value was set outside this method and
   374     // add edge to phantom object.
   375     add_pointsto_edge(ni, _phantom_object);
   376   }
   377 }
   380 //  Add an edge to node given by "to_i" from any field of adr_i whose offset
   381 //  matches "offset"  A deferred edge is added if to_i is a LocalVar, and
   382 //  a pointsto edge is added if it is a JavaObject
   384 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
   385   // No fields for NULL pointer.
   386   if (is_null_ptr(adr_i)) {
   387     return;
   388   }
   389   PointsToNode* an = ptnode_adr(adr_i);
   390   PointsToNode* to = ptnode_adr(to_i);
   391   bool deferred = (to->node_type() == PointsToNode::LocalVar);
   392   bool escaped  = (to_i == _phantom_object) && (offs == Type::OffsetTop);
   393   if (escaped) {
   394     // Values in fields escaped during call.
   395     assert(an->escape_state() >= PointsToNode::ArgEscape, "sanity");
   396     offs = Type::OffsetBot;
   397   }
   398   for (uint fe = 0; fe < an->edge_count(); fe++) {
   399     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   400     int fi = an->edge_target(fe);
   401     if (escaped) {
   402       set_escape_state(fi, PointsToNode::GlobalEscape);
   403     }
   404     PointsToNode* pf = ptnode_adr(fi);
   405     int po = pf->offset();
   406     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
   407       if (deferred)
   408         add_deferred_edge(fi, to_i);
   409       else
   410         add_pointsto_edge(fi, to_i);
   411     }
   412   }
   413 }
   415 // Add a deferred  edge from node given by "from_i" to any field of adr_i
   416 // whose offset matches "offset".
   417 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
   418   // No fields for NULL pointer.
   419   if (is_null_ptr(adr_i)) {
   420     return;
   421   }
   422   if (adr_i == _phantom_object) {
   423     // Add only one edge for unknown object.
   424     add_pointsto_edge(from_i, _phantom_object);
   425     return;
   426   }
   427   PointsToNode* an = ptnode_adr(adr_i);
   428   bool is_alloc = an->_node->is_Allocate();
   429   for (uint fe = 0; fe < an->edge_count(); fe++) {
   430     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   431     int fi = an->edge_target(fe);
   432     PointsToNode* pf = ptnode_adr(fi);
   433     int offset = pf->offset();
   434     if (!is_alloc) {
   435       // Assume the field was set outside this method if it is not Allocation
   436       add_pointsto_edge(fi, _phantom_object);
   437     }
   438     if (offset == offs || offset == Type::OffsetBot || offs == Type::OffsetBot) {
   439       add_deferred_edge(from_i, fi);
   440     }
   441   }
   442   // Some fields references (AddP) may still be missing
   443   // until Connection Graph construction is complete.
   444   // For example, loads from RAW pointers with offset 0
   445   // which don't have AddP.
   446   // A reference to phantom_object will be added if
   447   // a field reference is still missing after completing
   448   // Connection Graph (see remove_deferred()).
   449 }
   451 // Helper functions
   453 static Node* get_addp_base(Node *addp) {
   454   assert(addp->is_AddP(), "must be AddP");
   455   //
   456   // AddP cases for Base and Address inputs:
   457   // case #1. Direct object's field reference:
   458   //     Allocate
   459   //       |
   460   //     Proj #5 ( oop result )
   461   //       |
   462   //     CheckCastPP (cast to instance type)
   463   //      | |
   464   //     AddP  ( base == address )
   465   //
   466   // case #2. Indirect object's field reference:
   467   //      Phi
   468   //       |
   469   //     CastPP (cast to instance type)
   470   //      | |
   471   //     AddP  ( base == address )
   472   //
   473   // case #3. Raw object's field reference for Initialize node:
   474   //      Allocate
   475   //        |
   476   //      Proj #5 ( oop result )
   477   //  top   |
   478   //     \  |
   479   //     AddP  ( base == top )
   480   //
   481   // case #4. Array's element reference:
   482   //   {CheckCastPP | CastPP}
   483   //     |  | |
   484   //     |  AddP ( array's element offset )
   485   //     |  |
   486   //     AddP ( array's offset )
   487   //
   488   // case #5. Raw object's field reference for arraycopy stub call:
   489   //          The inline_native_clone() case when the arraycopy stub is called
   490   //          after the allocation before Initialize and CheckCastPP nodes.
   491   //      Allocate
   492   //        |
   493   //      Proj #5 ( oop result )
   494   //       | |
   495   //       AddP  ( base == address )
   496   //
   497   // case #6. Constant Pool, ThreadLocal, CastX2P or
   498   //          Raw object's field reference:
   499   //      {ConP, ThreadLocal, CastX2P, raw Load}
   500   //  top   |
   501   //     \  |
   502   //     AddP  ( base == top )
   503   //
   504   // case #7. Klass's field reference.
   505   //      LoadKlass
   506   //       | |
   507   //       AddP  ( base == address )
   508   //
   509   // case #8. narrow Klass's field reference.
   510   //      LoadNKlass
   511   //       |
   512   //      DecodeN
   513   //       | |
   514   //       AddP  ( base == address )
   515   //
   516   Node *base = addp->in(AddPNode::Base)->uncast();
   517   if (base->is_top()) { // The AddP case #3 and #6.
   518     base = addp->in(AddPNode::Address)->uncast();
   519     while (base->is_AddP()) {
   520       // Case #6 (unsafe access) may have several chained AddP nodes.
   521       assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
   522       base = base->in(AddPNode::Address)->uncast();
   523     }
   524     assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
   525            base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
   526            (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
   527            (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
   528   }
   529   return base;
   530 }
   532 static Node* find_second_addp(Node* addp, Node* n) {
   533   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
   535   Node* addp2 = addp->raw_out(0);
   536   if (addp->outcnt() == 1 && addp2->is_AddP() &&
   537       addp2->in(AddPNode::Base) == n &&
   538       addp2->in(AddPNode::Address) == addp) {
   540     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
   541     //
   542     // Find array's offset to push it on worklist first and
   543     // as result process an array's element offset first (pushed second)
   544     // to avoid CastPP for the array's offset.
   545     // Otherwise the inserted CastPP (LocalVar) will point to what
   546     // the AddP (Field) points to. Which would be wrong since
   547     // the algorithm expects the CastPP has the same point as
   548     // as AddP's base CheckCastPP (LocalVar).
   549     //
   550     //    ArrayAllocation
   551     //     |
   552     //    CheckCastPP
   553     //     |
   554     //    memProj (from ArrayAllocation CheckCastPP)
   555     //     |  ||
   556     //     |  ||   Int (element index)
   557     //     |  ||    |   ConI (log(element size))
   558     //     |  ||    |   /
   559     //     |  ||   LShift
   560     //     |  ||  /
   561     //     |  AddP (array's element offset)
   562     //     |  |
   563     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
   564     //     | / /
   565     //     AddP (array's offset)
   566     //      |
   567     //     Load/Store (memory operation on array's element)
   568     //
   569     return addp2;
   570   }
   571   return NULL;
   572 }
   574 //
   575 // Adjust the type and inputs of an AddP which computes the
   576 // address of a field of an instance
   577 //
   578 bool ConnectionGraph::split_AddP(Node *addp, Node *base,  PhaseGVN  *igvn) {
   579   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
   580   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
   581   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
   582   if (t == NULL) {
   583     // We are computing a raw address for a store captured by an Initialize
   584     // compute an appropriate address type (cases #3 and #5).
   585     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
   586     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
   587     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
   588     assert(offs != Type::OffsetBot, "offset must be a constant");
   589     t = base_t->add_offset(offs)->is_oopptr();
   590   }
   591   int inst_id =  base_t->instance_id();
   592   assert(!t->is_known_instance() || t->instance_id() == inst_id,
   593                              "old type must be non-instance or match new type");
   595   // The type 't' could be subclass of 'base_t'.
   596   // As result t->offset() could be large then base_t's size and it will
   597   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
   598   // constructor verifies correctness of the offset.
   599   //
   600   // It could happened on subclass's branch (from the type profiling
   601   // inlining) which was not eliminated during parsing since the exactness
   602   // of the allocation type was not propagated to the subclass type check.
   603   //
   604   // Or the type 't' could be not related to 'base_t' at all.
   605   // It could happened when CHA type is different from MDO type on a dead path
   606   // (for example, from instanceof check) which is not collapsed during parsing.
   607   //
   608   // Do nothing for such AddP node and don't process its users since
   609   // this code branch will go away.
   610   //
   611   if (!t->is_known_instance() &&
   612       !base_t->klass()->is_subtype_of(t->klass())) {
   613      return false; // bail out
   614   }
   616   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
   617   // Do NOT remove the next line: ensure a new alias index is allocated
   618   // for the instance type. Note: C++ will not remove it since the call
   619   // has side effect.
   620   int alias_idx = _compile->get_alias_index(tinst);
   621   igvn->set_type(addp, tinst);
   622   // record the allocation in the node map
   623   assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
   624   set_map(addp->_idx, get_map(base->_idx));
   626   // Set addp's Base and Address to 'base'.
   627   Node *abase = addp->in(AddPNode::Base);
   628   Node *adr   = addp->in(AddPNode::Address);
   629   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
   630       adr->in(0)->_idx == (uint)inst_id) {
   631     // Skip AddP cases #3 and #5.
   632   } else {
   633     assert(!abase->is_top(), "sanity"); // AddP case #3
   634     if (abase != base) {
   635       igvn->hash_delete(addp);
   636       addp->set_req(AddPNode::Base, base);
   637       if (abase == adr) {
   638         addp->set_req(AddPNode::Address, base);
   639       } else {
   640         // AddP case #4 (adr is array's element offset AddP node)
   641 #ifdef ASSERT
   642         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
   643         assert(adr->is_AddP() && atype != NULL &&
   644                atype->instance_id() == inst_id, "array's element offset should be processed first");
   645 #endif
   646       }
   647       igvn->hash_insert(addp);
   648     }
   649   }
   650   // Put on IGVN worklist since at least addp's type was changed above.
   651   record_for_optimizer(addp);
   652   return true;
   653 }
   655 //
   656 // Create a new version of orig_phi if necessary. Returns either the newly
   657 // created phi or an existing phi.  Sets create_new to indicate whether a new
   658 // phi was created.  Cache the last newly created phi in the node map.
   659 //
   660 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created) {
   661   Compile *C = _compile;
   662   new_created = false;
   663   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
   664   // nothing to do if orig_phi is bottom memory or matches alias_idx
   665   if (phi_alias_idx == alias_idx) {
   666     return orig_phi;
   667   }
   668   // Have we recently created a Phi for this alias index?
   669   PhiNode *result = get_map_phi(orig_phi->_idx);
   670   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
   671     return result;
   672   }
   673   // Previous check may fail when the same wide memory Phi was split into Phis
   674   // for different memory slices. Search all Phis for this region.
   675   if (result != NULL) {
   676     Node* region = orig_phi->in(0);
   677     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
   678       Node* phi = region->fast_out(i);
   679       if (phi->is_Phi() &&
   680           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
   681         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
   682         return phi->as_Phi();
   683       }
   684     }
   685   }
   686   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
   687     if (C->do_escape_analysis() == true && !C->failing()) {
   688       // Retry compilation without escape analysis.
   689       // If this is the first failure, the sentinel string will "stick"
   690       // to the Compile object, and the C2Compiler will see it and retry.
   691       C->record_failure(C2Compiler::retry_no_escape_analysis());
   692     }
   693     return NULL;
   694   }
   695   orig_phi_worklist.append_if_missing(orig_phi);
   696   const TypePtr *atype = C->get_adr_type(alias_idx);
   697   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
   698   C->copy_node_notes_to(result, orig_phi);
   699   igvn->set_type(result, result->bottom_type());
   700   record_for_optimizer(result);
   702   debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
   703   assert(pn == NULL || pn == orig_phi, "wrong node");
   704   set_map(orig_phi->_idx, result);
   705   ptnode_adr(orig_phi->_idx)->_node = orig_phi;
   707   new_created = true;
   708   return result;
   709 }
   711 //
   712 // Return a new version of Memory Phi "orig_phi" with the inputs having the
   713 // specified alias index.
   714 //
   715 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
   717   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
   718   Compile *C = _compile;
   719   bool new_phi_created;
   720   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
   721   if (!new_phi_created) {
   722     return result;
   723   }
   725   GrowableArray<PhiNode *>  phi_list;
   726   GrowableArray<uint>  cur_input;
   728   PhiNode *phi = orig_phi;
   729   uint idx = 1;
   730   bool finished = false;
   731   while(!finished) {
   732     while (idx < phi->req()) {
   733       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
   734       if (mem != NULL && mem->is_Phi()) {
   735         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
   736         if (new_phi_created) {
   737           // found an phi for which we created a new split, push current one on worklist and begin
   738           // processing new one
   739           phi_list.push(phi);
   740           cur_input.push(idx);
   741           phi = mem->as_Phi();
   742           result = newphi;
   743           idx = 1;
   744           continue;
   745         } else {
   746           mem = newphi;
   747         }
   748       }
   749       if (C->failing()) {
   750         return NULL;
   751       }
   752       result->set_req(idx++, mem);
   753     }
   754 #ifdef ASSERT
   755     // verify that the new Phi has an input for each input of the original
   756     assert( phi->req() == result->req(), "must have same number of inputs.");
   757     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
   758 #endif
   759     // Check if all new phi's inputs have specified alias index.
   760     // Otherwise use old phi.
   761     for (uint i = 1; i < phi->req(); i++) {
   762       Node* in = result->in(i);
   763       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
   764     }
   765     // we have finished processing a Phi, see if there are any more to do
   766     finished = (phi_list.length() == 0 );
   767     if (!finished) {
   768       phi = phi_list.pop();
   769       idx = cur_input.pop();
   770       PhiNode *prev_result = get_map_phi(phi->_idx);
   771       prev_result->set_req(idx++, result);
   772       result = prev_result;
   773     }
   774   }
   775   return result;
   776 }
   779 //
   780 // The next methods are derived from methods in MemNode.
   781 //
   782 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
   783   Node *mem = mmem;
   784   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
   785   // means an array I have not precisely typed yet.  Do not do any
   786   // alias stuff with it any time soon.
   787   if( toop->base() != Type::AnyPtr &&
   788       !(toop->klass() != NULL &&
   789         toop->klass()->is_java_lang_Object() &&
   790         toop->offset() == Type::OffsetBot) ) {
   791     mem = mmem->memory_at(alias_idx);
   792     // Update input if it is progress over what we have now
   793   }
   794   return mem;
   795 }
   797 //
   798 // Move memory users to their memory slices.
   799 //
   800 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn) {
   801   Compile* C = _compile;
   803   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
   804   assert(tp != NULL, "ptr type");
   805   int alias_idx = C->get_alias_index(tp);
   806   int general_idx = C->get_general_index(alias_idx);
   808   // Move users first
   809   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
   810     Node* use = n->fast_out(i);
   811     if (use->is_MergeMem()) {
   812       MergeMemNode* mmem = use->as_MergeMem();
   813       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
   814       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
   815         continue; // Nothing to do
   816       }
   817       // Replace previous general reference to mem node.
   818       uint orig_uniq = C->unique();
   819       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   820       assert(orig_uniq == C->unique(), "no new nodes");
   821       mmem->set_memory_at(general_idx, m);
   822       --imax;
   823       --i;
   824     } else if (use->is_MemBar()) {
   825       assert(!use->is_Initialize(), "initializing stores should not be moved");
   826       if (use->req() > MemBarNode::Precedent &&
   827           use->in(MemBarNode::Precedent) == n) {
   828         // Don't move related membars.
   829         record_for_optimizer(use);
   830         continue;
   831       }
   832       tp = use->as_MemBar()->adr_type()->isa_ptr();
   833       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
   834           alias_idx == general_idx) {
   835         continue; // Nothing to do
   836       }
   837       // Move to general memory slice.
   838       uint orig_uniq = C->unique();
   839       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   840       assert(orig_uniq == C->unique(), "no new nodes");
   841       igvn->hash_delete(use);
   842       imax -= use->replace_edge(n, m);
   843       igvn->hash_insert(use);
   844       record_for_optimizer(use);
   845       --i;
   846 #ifdef ASSERT
   847     } else if (use->is_Mem()) {
   848       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
   849         // Don't move related cardmark.
   850         continue;
   851       }
   852       // Memory nodes should have new memory input.
   853       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
   854       assert(tp != NULL, "ptr type");
   855       int idx = C->get_alias_index(tp);
   856       assert(get_map(use->_idx) != NULL || idx == alias_idx,
   857              "Following memory nodes should have new memory input or be on the same memory slice");
   858     } else if (use->is_Phi()) {
   859       // Phi nodes should be split and moved already.
   860       tp = use->as_Phi()->adr_type()->isa_ptr();
   861       assert(tp != NULL, "ptr type");
   862       int idx = C->get_alias_index(tp);
   863       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
   864     } else {
   865       use->dump();
   866       assert(false, "should not be here");
   867 #endif
   868     }
   869   }
   870 }
   872 //
   873 // Search memory chain of "mem" to find a MemNode whose address
   874 // is the specified alias index.
   875 //
   876 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *phase) {
   877   if (orig_mem == NULL)
   878     return orig_mem;
   879   Compile* C = phase->C;
   880   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
   881   bool is_instance = (toop != NULL) && toop->is_known_instance();
   882   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   883   Node *prev = NULL;
   884   Node *result = orig_mem;
   885   while (prev != result) {
   886     prev = result;
   887     if (result == start_mem)
   888       break;  // hit one of our sentinels
   889     if (result->is_Mem()) {
   890       const Type *at = phase->type(result->in(MemNode::Address));
   891       if (at == Type::TOP)
   892         break; // Dead
   893       assert (at->isa_ptr() != NULL, "pointer type required.");
   894       int idx = C->get_alias_index(at->is_ptr());
   895       if (idx == alias_idx)
   896         break; // Found
   897       if (!is_instance && (at->isa_oopptr() == NULL ||
   898                            !at->is_oopptr()->is_known_instance())) {
   899         break; // Do not skip store to general memory slice.
   900       }
   901       result = result->in(MemNode::Memory);
   902     }
   903     if (!is_instance)
   904       continue;  // don't search further for non-instance types
   905     // skip over a call which does not affect this memory slice
   906     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
   907       Node *proj_in = result->in(0);
   908       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
   909         break;  // hit one of our sentinels
   910       } else if (proj_in->is_Call()) {
   911         CallNode *call = proj_in->as_Call();
   912         if (!call->may_modify(toop, phase)) {
   913           result = call->in(TypeFunc::Memory);
   914         }
   915       } else if (proj_in->is_Initialize()) {
   916         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
   917         // Stop if this is the initialization for the object instance which
   918         // which contains this memory slice, otherwise skip over it.
   919         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
   920           result = proj_in->in(TypeFunc::Memory);
   921         }
   922       } else if (proj_in->is_MemBar()) {
   923         result = proj_in->in(TypeFunc::Memory);
   924       }
   925     } else if (result->is_MergeMem()) {
   926       MergeMemNode *mmem = result->as_MergeMem();
   927       result = step_through_mergemem(mmem, alias_idx, toop);
   928       if (result == mmem->base_memory()) {
   929         // Didn't find instance memory, search through general slice recursively.
   930         result = mmem->memory_at(C->get_general_index(alias_idx));
   931         result = find_inst_mem(result, alias_idx, orig_phis, phase);
   932         if (C->failing()) {
   933           return NULL;
   934         }
   935         mmem->set_memory_at(alias_idx, result);
   936       }
   937     } else if (result->is_Phi() &&
   938                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
   939       Node *un = result->as_Phi()->unique_input(phase);
   940       if (un != NULL) {
   941         orig_phis.append_if_missing(result->as_Phi());
   942         result = un;
   943       } else {
   944         break;
   945       }
   946     } else if (result->is_ClearArray()) {
   947       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
   948         // Can not bypass initialization of the instance
   949         // we are looking for.
   950         break;
   951       }
   952       // Otherwise skip it (the call updated 'result' value).
   953     } else if (result->Opcode() == Op_SCMemProj) {
   954       assert(result->in(0)->is_LoadStore(), "sanity");
   955       const Type *at = phase->type(result->in(0)->in(MemNode::Address));
   956       if (at != Type::TOP) {
   957         assert (at->isa_ptr() != NULL, "pointer type required.");
   958         int idx = C->get_alias_index(at->is_ptr());
   959         assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
   960         break;
   961       }
   962       result = result->in(0)->in(MemNode::Memory);
   963     }
   964   }
   965   if (result->is_Phi()) {
   966     PhiNode *mphi = result->as_Phi();
   967     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
   968     const TypePtr *t = mphi->adr_type();
   969     if (!is_instance) {
   970       // Push all non-instance Phis on the orig_phis worklist to update inputs
   971       // during Phase 4 if needed.
   972       orig_phis.append_if_missing(mphi);
   973     } else if (C->get_alias_index(t) != alias_idx) {
   974       // Create a new Phi with the specified alias index type.
   975       result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
   976     }
   977   }
   978   // the result is either MemNode, PhiNode, InitializeNode.
   979   return result;
   980 }
   982 //
   983 //  Convert the types of unescaped object to instance types where possible,
   984 //  propagate the new type information through the graph, and update memory
   985 //  edges and MergeMem inputs to reflect the new type.
   986 //
   987 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
   988 //  The processing is done in 4 phases:
   989 //
   990 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
   991 //            types for the CheckCastPP for allocations where possible.
   992 //            Propagate the the new types through users as follows:
   993 //               casts and Phi:  push users on alloc_worklist
   994 //               AddP:  cast Base and Address inputs to the instance type
   995 //                      push any AddP users on alloc_worklist and push any memnode
   996 //                      users onto memnode_worklist.
   997 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
   998 //            search the Memory chain for a store with the appropriate type
   999 //            address type.  If a Phi is found, create a new version with
  1000 //            the appropriate memory slices from each of the Phi inputs.
  1001 //            For stores, process the users as follows:
  1002 //               MemNode:  push on memnode_worklist
  1003 //               MergeMem: push on mergemem_worklist
  1004 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
  1005 //            moving the first node encountered of each  instance type to the
  1006 //            the input corresponding to its alias index.
  1007 //            appropriate memory slice.
  1008 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
  1009 //
  1010 // In the following example, the CheckCastPP nodes are the cast of allocation
  1011 // results and the allocation of node 29 is unescaped and eligible to be an
  1012 // instance type.
  1013 //
  1014 // We start with:
  1015 //
  1016 //     7 Parm #memory
  1017 //    10  ConI  "12"
  1018 //    19  CheckCastPP   "Foo"
  1019 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
  1020 //    29  CheckCastPP   "Foo"
  1021 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
  1022 //
  1023 //    40  StoreP  25   7  20   ... alias_index=4
  1024 //    50  StoreP  35  40  30   ... alias_index=4
  1025 //    60  StoreP  45  50  20   ... alias_index=4
  1026 //    70  LoadP    _  60  30   ... alias_index=4
  1027 //    80  Phi     75  50  60   Memory alias_index=4
  1028 //    90  LoadP    _  80  30   ... alias_index=4
  1029 //   100  LoadP    _  80  20   ... alias_index=4
  1030 //
  1031 //
  1032 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
  1033 // and creating a new alias index for node 30.  This gives:
  1034 //
  1035 //     7 Parm #memory
  1036 //    10  ConI  "12"
  1037 //    19  CheckCastPP   "Foo"
  1038 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
  1039 //    29  CheckCastPP   "Foo"  iid=24
  1040 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
  1041 //
  1042 //    40  StoreP  25   7  20   ... alias_index=4
  1043 //    50  StoreP  35  40  30   ... alias_index=6
  1044 //    60  StoreP  45  50  20   ... alias_index=4
  1045 //    70  LoadP    _  60  30   ... alias_index=6
  1046 //    80  Phi     75  50  60   Memory alias_index=4
  1047 //    90  LoadP    _  80  30   ... alias_index=6
  1048 //   100  LoadP    _  80  20   ... alias_index=4
  1049 //
  1050 // In phase 2, new memory inputs are computed for the loads and stores,
  1051 // And a new version of the phi is created.  In phase 4, the inputs to
  1052 // node 80 are updated and then the memory nodes are updated with the
  1053 // values computed in phase 2.  This results in:
  1054 //
  1055 //     7 Parm #memory
  1056 //    10  ConI  "12"
  1057 //    19  CheckCastPP   "Foo"
  1058 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
  1059 //    29  CheckCastPP   "Foo"  iid=24
  1060 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
  1061 //
  1062 //    40  StoreP  25  7   20   ... alias_index=4
  1063 //    50  StoreP  35  7   30   ... alias_index=6
  1064 //    60  StoreP  45  40  20   ... alias_index=4
  1065 //    70  LoadP    _  50  30   ... alias_index=6
  1066 //    80  Phi     75  40  60   Memory alias_index=4
  1067 //   120  Phi     75  50  50   Memory alias_index=6
  1068 //    90  LoadP    _ 120  30   ... alias_index=6
  1069 //   100  LoadP    _  80  20   ... alias_index=4
  1070 //
  1071 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
  1072   GrowableArray<Node *>  memnode_worklist;
  1073   GrowableArray<PhiNode *>  orig_phis;
  1075   PhaseIterGVN  *igvn = _igvn;
  1076   uint new_index_start = (uint) _compile->num_alias_types();
  1077   Arena* arena = Thread::current()->resource_area();
  1078   VectorSet visited(arena);
  1081   //  Phase 1:  Process possible allocations from alloc_worklist.
  1082   //  Create instance types for the CheckCastPP for allocations where possible.
  1083   //
  1084   // (Note: don't forget to change the order of the second AddP node on
  1085   //  the alloc_worklist if the order of the worklist processing is changed,
  1086   //  see the comment in find_second_addp().)
  1087   //
  1088   while (alloc_worklist.length() != 0) {
  1089     Node *n = alloc_worklist.pop();
  1090     uint ni = n->_idx;
  1091     const TypeOopPtr* tinst = NULL;
  1092     if (n->is_Call()) {
  1093       CallNode *alloc = n->as_Call();
  1094       // copy escape information to call node
  1095       PointsToNode* ptn = ptnode_adr(alloc->_idx);
  1096       PointsToNode::EscapeState es = escape_state(alloc);
  1097       // We have an allocation or call which returns a Java object,
  1098       // see if it is unescaped.
  1099       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
  1100         continue;
  1102       // Find CheckCastPP for the allocate or for the return value of a call
  1103       n = alloc->result_cast();
  1104       if (n == NULL) {            // No uses except Initialize node
  1105         if (alloc->is_Allocate()) {
  1106           // Set the scalar_replaceable flag for allocation
  1107           // so it could be eliminated if it has no uses.
  1108           alloc->as_Allocate()->_is_scalar_replaceable = true;
  1110         continue;
  1112       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
  1113         assert(!alloc->is_Allocate(), "allocation should have unique type");
  1114         continue;
  1117       // The inline code for Object.clone() casts the allocation result to
  1118       // java.lang.Object and then to the actual type of the allocated
  1119       // object. Detect this case and use the second cast.
  1120       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
  1121       // the allocation result is cast to java.lang.Object and then
  1122       // to the actual Array type.
  1123       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
  1124           && (alloc->is_AllocateArray() ||
  1125               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
  1126         Node *cast2 = NULL;
  1127         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1128           Node *use = n->fast_out(i);
  1129           if (use->is_CheckCastPP()) {
  1130             cast2 = use;
  1131             break;
  1134         if (cast2 != NULL) {
  1135           n = cast2;
  1136         } else {
  1137           // Non-scalar replaceable if the allocation type is unknown statically
  1138           // (reflection allocation), the object can't be restored during
  1139           // deoptimization without precise type.
  1140           continue;
  1143       if (alloc->is_Allocate()) {
  1144         // Set the scalar_replaceable flag for allocation
  1145         // so it could be eliminated.
  1146         alloc->as_Allocate()->_is_scalar_replaceable = true;
  1148       set_escape_state(n->_idx, es); // CheckCastPP escape state
  1149       // in order for an object to be scalar-replaceable, it must be:
  1150       //   - a direct allocation (not a call returning an object)
  1151       //   - non-escaping
  1152       //   - eligible to be a unique type
  1153       //   - not determined to be ineligible by escape analysis
  1154       assert(ptnode_adr(alloc->_idx)->_node != NULL &&
  1155              ptnode_adr(n->_idx)->_node != NULL, "should be registered");
  1156       set_map(alloc->_idx, n);
  1157       set_map(n->_idx, alloc);
  1158       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
  1159       if (t == NULL)
  1160         continue;  // not a TypeOopPtr
  1161       tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
  1162       igvn->hash_delete(n);
  1163       igvn->set_type(n,  tinst);
  1164       n->raise_bottom_type(tinst);
  1165       igvn->hash_insert(n);
  1166       record_for_optimizer(n);
  1167       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
  1169         // First, put on the worklist all Field edges from Connection Graph
  1170         // which is more accurate then putting immediate users from Ideal Graph.
  1171         for (uint e = 0; e < ptn->edge_count(); e++) {
  1172           Node *use = ptnode_adr(ptn->edge_target(e))->_node;
  1173           assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
  1174                  "only AddP nodes are Field edges in CG");
  1175           if (use->outcnt() > 0) { // Don't process dead nodes
  1176             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
  1177             if (addp2 != NULL) {
  1178               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1179               alloc_worklist.append_if_missing(addp2);
  1181             alloc_worklist.append_if_missing(use);
  1185         // An allocation may have an Initialize which has raw stores. Scan
  1186         // the users of the raw allocation result and push AddP users
  1187         // on alloc_worklist.
  1188         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
  1189         assert (raw_result != NULL, "must have an allocation result");
  1190         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
  1191           Node *use = raw_result->fast_out(i);
  1192           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
  1193             Node* addp2 = find_second_addp(use, raw_result);
  1194             if (addp2 != NULL) {
  1195               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1196               alloc_worklist.append_if_missing(addp2);
  1198             alloc_worklist.append_if_missing(use);
  1199           } else if (use->is_MemBar()) {
  1200             memnode_worklist.append_if_missing(use);
  1204     } else if (n->is_AddP()) {
  1205       VectorSet* ptset = PointsTo(get_addp_base(n));
  1206       assert(ptset->Size() == 1, "AddP address is unique");
  1207       uint elem = ptset->getelem(); // Allocation node's index
  1208       if (elem == _phantom_object) {
  1209         assert(false, "escaped allocation");
  1210         continue; // Assume the value was set outside this method.
  1212       Node *base = get_map(elem);  // CheckCastPP node
  1213       if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
  1214       tinst = igvn->type(base)->isa_oopptr();
  1215     } else if (n->is_Phi() ||
  1216                n->is_CheckCastPP() ||
  1217                n->is_EncodeP() ||
  1218                n->is_DecodeN() ||
  1219                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
  1220       if (visited.test_set(n->_idx)) {
  1221         assert(n->is_Phi(), "loops only through Phi's");
  1222         continue;  // already processed
  1224       VectorSet* ptset = PointsTo(n);
  1225       if (ptset->Size() == 1) {
  1226         uint elem = ptset->getelem(); // Allocation node's index
  1227         if (elem == _phantom_object) {
  1228           assert(false, "escaped allocation");
  1229           continue; // Assume the value was set outside this method.
  1231         Node *val = get_map(elem);   // CheckCastPP node
  1232         TypeNode *tn = n->as_Type();
  1233         tinst = igvn->type(val)->isa_oopptr();
  1234         assert(tinst != NULL && tinst->is_known_instance() &&
  1235                (uint)tinst->instance_id() == elem , "instance type expected.");
  1237         const Type *tn_type = igvn->type(tn);
  1238         const TypeOopPtr *tn_t;
  1239         if (tn_type->isa_narrowoop()) {
  1240           tn_t = tn_type->make_ptr()->isa_oopptr();
  1241         } else {
  1242           tn_t = tn_type->isa_oopptr();
  1245         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
  1246           if (tn_type->isa_narrowoop()) {
  1247             tn_type = tinst->make_narrowoop();
  1248           } else {
  1249             tn_type = tinst;
  1251           igvn->hash_delete(tn);
  1252           igvn->set_type(tn, tn_type);
  1253           tn->set_type(tn_type);
  1254           igvn->hash_insert(tn);
  1255           record_for_optimizer(n);
  1256         } else {
  1257           assert(tn_type == TypePtr::NULL_PTR ||
  1258                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
  1259                  "unexpected type");
  1260           continue; // Skip dead path with different type
  1263     } else {
  1264       debug_only(n->dump();)
  1265       assert(false, "EA: unexpected node");
  1266       continue;
  1268     // push allocation's users on appropriate worklist
  1269     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1270       Node *use = n->fast_out(i);
  1271       if(use->is_Mem() && use->in(MemNode::Address) == n) {
  1272         // Load/store to instance's field
  1273         memnode_worklist.append_if_missing(use);
  1274       } else if (use->is_MemBar()) {
  1275         memnode_worklist.append_if_missing(use);
  1276       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
  1277         Node* addp2 = find_second_addp(use, n);
  1278         if (addp2 != NULL) {
  1279           alloc_worklist.append_if_missing(addp2);
  1281         alloc_worklist.append_if_missing(use);
  1282       } else if (use->is_Phi() ||
  1283                  use->is_CheckCastPP() ||
  1284                  use->is_EncodeP() ||
  1285                  use->is_DecodeN() ||
  1286                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
  1287         alloc_worklist.append_if_missing(use);
  1288 #ifdef ASSERT
  1289       } else if (use->is_Mem()) {
  1290         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
  1291       } else if (use->is_MergeMem()) {
  1292         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1293       } else if (use->is_SafePoint()) {
  1294         // Look for MergeMem nodes for calls which reference unique allocation
  1295         // (through CheckCastPP nodes) even for debug info.
  1296         Node* m = use->in(TypeFunc::Memory);
  1297         if (m->is_MergeMem()) {
  1298           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1300       } else {
  1301         uint op = use->Opcode();
  1302         if (!(op == Op_CmpP || op == Op_Conv2B ||
  1303               op == Op_CastP2X || op == Op_StoreCM ||
  1304               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
  1305               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1306           n->dump();
  1307           use->dump();
  1308           assert(false, "EA: missing allocation reference path");
  1310 #endif
  1315   // New alias types were created in split_AddP().
  1316   uint new_index_end = (uint) _compile->num_alias_types();
  1318   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
  1319   //            compute new values for Memory inputs  (the Memory inputs are not
  1320   //            actually updated until phase 4.)
  1321   if (memnode_worklist.length() == 0)
  1322     return;  // nothing to do
  1324   while (memnode_worklist.length() != 0) {
  1325     Node *n = memnode_worklist.pop();
  1326     if (visited.test_set(n->_idx))
  1327       continue;
  1328     if (n->is_Phi() || n->is_ClearArray()) {
  1329       // we don't need to do anything, but the users must be pushed
  1330     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
  1331       // we don't need to do anything, but the users must be pushed
  1332       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
  1333       if (n == NULL)
  1334         continue;
  1335     } else {
  1336       assert(n->is_Mem(), "memory node required.");
  1337       Node *addr = n->in(MemNode::Address);
  1338       const Type *addr_t = igvn->type(addr);
  1339       if (addr_t == Type::TOP)
  1340         continue;
  1341       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
  1342       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
  1343       assert ((uint)alias_idx < new_index_end, "wrong alias index");
  1344       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
  1345       if (_compile->failing()) {
  1346         return;
  1348       if (mem != n->in(MemNode::Memory)) {
  1349         // We delay the memory edge update since we need old one in
  1350         // MergeMem code below when instances memory slices are separated.
  1351         debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
  1352         assert(pn == NULL || pn == n, "wrong node");
  1353         set_map(n->_idx, mem);
  1354         ptnode_adr(n->_idx)->_node = n;
  1356       if (n->is_Load()) {
  1357         continue;  // don't push users
  1358       } else if (n->is_LoadStore()) {
  1359         // get the memory projection
  1360         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1361           Node *use = n->fast_out(i);
  1362           if (use->Opcode() == Op_SCMemProj) {
  1363             n = use;
  1364             break;
  1367         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
  1370     // push user on appropriate worklist
  1371     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1372       Node *use = n->fast_out(i);
  1373       if (use->is_Phi() || use->is_ClearArray()) {
  1374         memnode_worklist.append_if_missing(use);
  1375       } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
  1376         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
  1377           continue;
  1378         memnode_worklist.append_if_missing(use);
  1379       } else if (use->is_MemBar()) {
  1380         memnode_worklist.append_if_missing(use);
  1381 #ifdef ASSERT
  1382       } else if(use->is_Mem()) {
  1383         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
  1384       } else if (use->is_MergeMem()) {
  1385         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1386       } else {
  1387         uint op = use->Opcode();
  1388         if (!(op == Op_StoreCM ||
  1389               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
  1390                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
  1391               op == Op_AryEq || op == Op_StrComp ||
  1392               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1393           n->dump();
  1394           use->dump();
  1395           assert(false, "EA: missing memory path");
  1397 #endif
  1402   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
  1403   //            Walk each memory slice moving the first node encountered of each
  1404   //            instance type to the the input corresponding to its alias index.
  1405   uint length = _mergemem_worklist.length();
  1406   for( uint next = 0; next < length; ++next ) {
  1407     MergeMemNode* nmm = _mergemem_worklist.at(next);
  1408     assert(!visited.test_set(nmm->_idx), "should not be visited before");
  1409     // Note: we don't want to use MergeMemStream here because we only want to
  1410     // scan inputs which exist at the start, not ones we add during processing.
  1411     // Note 2: MergeMem may already contains instance memory slices added
  1412     // during find_inst_mem() call when memory nodes were processed above.
  1413     igvn->hash_delete(nmm);
  1414     uint nslices = nmm->req();
  1415     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
  1416       Node* mem = nmm->in(i);
  1417       Node* cur = NULL;
  1418       if (mem == NULL || mem->is_top())
  1419         continue;
  1420       // First, update mergemem by moving memory nodes to corresponding slices
  1421       // if their type became more precise since this mergemem was created.
  1422       while (mem->is_Mem()) {
  1423         const Type *at = igvn->type(mem->in(MemNode::Address));
  1424         if (at != Type::TOP) {
  1425           assert (at->isa_ptr() != NULL, "pointer type required.");
  1426           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
  1427           if (idx == i) {
  1428             if (cur == NULL)
  1429               cur = mem;
  1430           } else {
  1431             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
  1432               nmm->set_memory_at(idx, mem);
  1436         mem = mem->in(MemNode::Memory);
  1438       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
  1439       // Find any instance of the current type if we haven't encountered
  1440       // already a memory slice of the instance along the memory chain.
  1441       for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1442         if((uint)_compile->get_general_index(ni) == i) {
  1443           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
  1444           if (nmm->is_empty_memory(m)) {
  1445             Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
  1446             if (_compile->failing()) {
  1447               return;
  1449             nmm->set_memory_at(ni, result);
  1454     // Find the rest of instances values
  1455     for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1456       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
  1457       Node* result = step_through_mergemem(nmm, ni, tinst);
  1458       if (result == nmm->base_memory()) {
  1459         // Didn't find instance memory, search through general slice recursively.
  1460         result = nmm->memory_at(_compile->get_general_index(ni));
  1461         result = find_inst_mem(result, ni, orig_phis, igvn);
  1462         if (_compile->failing()) {
  1463           return;
  1465         nmm->set_memory_at(ni, result);
  1468     igvn->hash_insert(nmm);
  1469     record_for_optimizer(nmm);
  1472   //  Phase 4:  Update the inputs of non-instance memory Phis and
  1473   //            the Memory input of memnodes
  1474   // First update the inputs of any non-instance Phi's from
  1475   // which we split out an instance Phi.  Note we don't have
  1476   // to recursively process Phi's encounted on the input memory
  1477   // chains as is done in split_memory_phi() since they  will
  1478   // also be processed here.
  1479   for (int j = 0; j < orig_phis.length(); j++) {
  1480     PhiNode *phi = orig_phis.at(j);
  1481     int alias_idx = _compile->get_alias_index(phi->adr_type());
  1482     igvn->hash_delete(phi);
  1483     for (uint i = 1; i < phi->req(); i++) {
  1484       Node *mem = phi->in(i);
  1485       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
  1486       if (_compile->failing()) {
  1487         return;
  1489       if (mem != new_mem) {
  1490         phi->set_req(i, new_mem);
  1493     igvn->hash_insert(phi);
  1494     record_for_optimizer(phi);
  1497   // Update the memory inputs of MemNodes with the value we computed
  1498   // in Phase 2 and move stores memory users to corresponding memory slices.
  1500   // Disable memory split verification code until the fix for 6984348.
  1501   // Currently it produces false negative results since it does not cover all cases.
  1502 #if 0 // ifdef ASSERT
  1503   visited.Reset();
  1504   Node_Stack old_mems(arena, _compile->unique() >> 2);
  1505 #endif
  1506   for (uint i = 0; i < nodes_size(); i++) {
  1507     Node *nmem = get_map(i);
  1508     if (nmem != NULL) {
  1509       Node *n = ptnode_adr(i)->_node;
  1510       assert(n != NULL, "sanity");
  1511       if (n->is_Mem()) {
  1512 #if 0 // ifdef ASSERT
  1513         Node* old_mem = n->in(MemNode::Memory);
  1514         if (!visited.test_set(old_mem->_idx)) {
  1515           old_mems.push(old_mem, old_mem->outcnt());
  1517 #endif
  1518         assert(n->in(MemNode::Memory) != nmem, "sanity");
  1519         if (!n->is_Load()) {
  1520           // Move memory users of a store first.
  1521           move_inst_mem(n, orig_phis, igvn);
  1523         // Now update memory input
  1524         igvn->hash_delete(n);
  1525         n->set_req(MemNode::Memory, nmem);
  1526         igvn->hash_insert(n);
  1527         record_for_optimizer(n);
  1528       } else {
  1529         assert(n->is_Allocate() || n->is_CheckCastPP() ||
  1530                n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
  1534 #if 0 // ifdef ASSERT
  1535   // Verify that memory was split correctly
  1536   while (old_mems.is_nonempty()) {
  1537     Node* old_mem = old_mems.node();
  1538     uint  old_cnt = old_mems.index();
  1539     old_mems.pop();
  1540     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
  1542 #endif
  1545 bool ConnectionGraph::has_candidates(Compile *C) {
  1546   // EA brings benefits only when the code has allocations and/or locks which
  1547   // are represented by ideal Macro nodes.
  1548   int cnt = C->macro_count();
  1549   for( int i=0; i < cnt; i++ ) {
  1550     Node *n = C->macro_node(i);
  1551     if ( n->is_Allocate() )
  1552       return true;
  1553     if( n->is_Lock() ) {
  1554       Node* obj = n->as_Lock()->obj_node()->uncast();
  1555       if( !(obj->is_Parm() || obj->is_Con()) )
  1556         return true;
  1559   return false;
  1562 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  1563   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
  1564   // to create space for them in ConnectionGraph::_nodes[].
  1565   Node* oop_null = igvn->zerocon(T_OBJECT);
  1566   Node* noop_null = igvn->zerocon(T_NARROWOOP);
  1568   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
  1569   // Perform escape analysis
  1570   if (congraph->compute_escape()) {
  1571     // There are non escaping objects.
  1572     C->set_congraph(congraph);
  1575   // Cleanup.
  1576   if (oop_null->outcnt() == 0)
  1577     igvn->hash_delete(oop_null);
  1578   if (noop_null->outcnt() == 0)
  1579     igvn->hash_delete(noop_null);
  1582 bool ConnectionGraph::compute_escape() {
  1583   Compile* C = _compile;
  1585   // 1. Populate Connection Graph (CG) with Ideal nodes.
  1587   Unique_Node_List worklist_init;
  1588   worklist_init.map(C->unique(), NULL);  // preallocate space
  1590   // Initialize worklist
  1591   if (C->root() != NULL) {
  1592     worklist_init.push(C->root());
  1595   GrowableArray<Node*> alloc_worklist;
  1596   GrowableArray<Node*> addp_worklist;
  1597   GrowableArray<Node*> ptr_cmp_worklist;
  1598   GrowableArray<Node*> storestore_worklist;
  1599   PhaseGVN* igvn = _igvn;
  1601   // Push all useful nodes onto CG list and set their type.
  1602   for( uint next = 0; next < worklist_init.size(); ++next ) {
  1603     Node* n = worklist_init.at(next);
  1604     record_for_escape_analysis(n, igvn);
  1605     // Only allocations and java static calls results are checked
  1606     // for an escape status. See process_call_result() below.
  1607     if (n->is_Allocate() || n->is_CallStaticJava() &&
  1608         ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
  1609       alloc_worklist.append(n);
  1610     } else if(n->is_AddP()) {
  1611       // Collect address nodes. Use them during stage 3 below
  1612       // to build initial connection graph field edges.
  1613       addp_worklist.append(n);
  1614     } else if (n->is_MergeMem()) {
  1615       // Collect all MergeMem nodes to add memory slices for
  1616       // scalar replaceable objects in split_unique_types().
  1617       _mergemem_worklist.append(n->as_MergeMem());
  1618     } else if (OptimizePtrCompare && n->is_Cmp() &&
  1619                (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
  1620       // Compare pointers nodes
  1621       ptr_cmp_worklist.append(n);
  1622     } else if (n->is_MemBarStoreStore()) {
  1623       // Collect all MemBarStoreStore nodes so that depending on the
  1624       // escape status of the associated Allocate node some of them
  1625       // may be eliminated.
  1626       storestore_worklist.append(n);
  1628     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1629       Node* m = n->fast_out(i);   // Get user
  1630       worklist_init.push(m);
  1634   if (alloc_worklist.length() == 0) {
  1635     _collecting = false;
  1636     return false; // Nothing to do.
  1639   // 2. First pass to create simple CG edges (doesn't require to walk CG).
  1640   uint delayed_size = _delayed_worklist.size();
  1641   for( uint next = 0; next < delayed_size; ++next ) {
  1642     Node* n = _delayed_worklist.at(next);
  1643     build_connection_graph(n, igvn);
  1646   // 3. Pass to create initial fields edges (JavaObject -F-> AddP)
  1647   //    to reduce number of iterations during stage 4 below.
  1648   uint addp_length = addp_worklist.length();
  1649   for( uint next = 0; next < addp_length; ++next ) {
  1650     Node* n = addp_worklist.at(next);
  1651     Node* base = get_addp_base(n);
  1652     if (base->is_Proj() && base->in(0)->is_Call())
  1653       base = base->in(0);
  1654     PointsToNode::NodeType nt = ptnode_adr(base->_idx)->node_type();
  1655     if (nt == PointsToNode::JavaObject) {
  1656       build_connection_graph(n, igvn);
  1660   GrowableArray<int> cg_worklist;
  1661   cg_worklist.append(_phantom_object);
  1662   GrowableArray<uint>  worklist;
  1664   // 4. Build Connection Graph which need
  1665   //    to walk the connection graph.
  1666   _progress = false;
  1667   for (uint ni = 0; ni < nodes_size(); ni++) {
  1668     PointsToNode* ptn = ptnode_adr(ni);
  1669     Node *n = ptn->_node;
  1670     if (n != NULL) { // Call, AddP, LoadP, StoreP
  1671       build_connection_graph(n, igvn);
  1672       if (ptn->node_type() != PointsToNode::UnknownType)
  1673         cg_worklist.append(n->_idx); // Collect CG nodes
  1674       if (!_processed.test(n->_idx))
  1675         worklist.append(n->_idx); // Collect C/A/L/S nodes
  1679   // After IGVN user nodes may have smaller _idx than
  1680   // their inputs so they will be processed first in
  1681   // previous loop. Because of that not all Graph
  1682   // edges will be created. Walk over interesting
  1683   // nodes again until no new edges are created.
  1684   //
  1685   // Normally only 1-3 passes needed to build
  1686   // Connection Graph depending on graph complexity.
  1687   // Observed 8 passes in jvm2008 compiler.compiler.
  1688   // Set limit to 20 to catch situation when something
  1689   // did go wrong and recompile the method without EA.
  1690   // Also limit build time to 30 sec (60 in debug VM).
  1692 #define CG_BUILD_ITER_LIMIT 20
  1694 #ifdef ASSERT
  1695 #define CG_BUILD_TIME_LIMIT 60.0
  1696 #else
  1697 #define CG_BUILD_TIME_LIMIT 30.0
  1698 #endif
  1700   uint length = worklist.length();
  1701   int iterations = 0;
  1702   elapsedTimer time;
  1703   while(_progress &&
  1704         (iterations++   < CG_BUILD_ITER_LIMIT) &&
  1705         (time.seconds() < CG_BUILD_TIME_LIMIT)) {
  1706     time.start();
  1707     _progress = false;
  1708     for( uint next = 0; next < length; ++next ) {
  1709       int ni = worklist.at(next);
  1710       PointsToNode* ptn = ptnode_adr(ni);
  1711       Node* n = ptn->_node;
  1712       assert(n != NULL, "should be known node");
  1713       build_connection_graph(n, igvn);
  1715     time.stop();
  1717   if ((iterations     >= CG_BUILD_ITER_LIMIT) ||
  1718       (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
  1719     assert(false, err_msg("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
  1720            time.seconds(), iterations, nodes_size(), length));
  1721     // Possible infinite build_connection_graph loop,
  1722     // bailout (no changes to ideal graph were made).
  1723     _collecting = false;
  1724     return false;
  1726 #undef CG_BUILD_ITER_LIMIT
  1727 #undef CG_BUILD_TIME_LIMIT
  1729   // 5. Propagate escaped states.
  1730   worklist.clear();
  1732   // mark all nodes reachable from GlobalEscape nodes
  1733   (void)propagate_escape_state(&cg_worklist, &worklist, PointsToNode::GlobalEscape);
  1735   // mark all nodes reachable from ArgEscape nodes
  1736   bool has_non_escaping_obj = propagate_escape_state(&cg_worklist, &worklist, PointsToNode::ArgEscape);
  1738   Arena* arena = Thread::current()->resource_area();
  1739   VectorSet visited(arena);
  1741   // 6. Find fields initializing values for not escaped allocations
  1742   uint alloc_length = alloc_worklist.length();
  1743   for (uint next = 0; next < alloc_length; ++next) {
  1744     Node* n = alloc_worklist.at(next);
  1745     PointsToNode::EscapeState es = ptnode_adr(n->_idx)->escape_state();
  1746     if (es == PointsToNode::NoEscape) {
  1747       has_non_escaping_obj = true;
  1748       if (n->is_Allocate()) {
  1749         find_init_values(n, &visited, igvn);
  1750         // The object allocated by this Allocate node will never be
  1751         // seen by an other thread. Mark it so that when it is
  1752         // expanded no MemBarStoreStore is added.
  1753         n->as_Allocate()->initialization()->set_does_not_escape();
  1755     } else if ((es == PointsToNode::ArgEscape) && n->is_Allocate()) {
  1756       // Same as above. Mark this Allocate node so that when it is
  1757       // expanded no MemBarStoreStore is added.
  1758       n->as_Allocate()->initialization()->set_does_not_escape();
  1762   uint cg_length = cg_worklist.length();
  1764   // Skip the rest of code if all objects escaped.
  1765   if (!has_non_escaping_obj) {
  1766     cg_length = 0;
  1767     addp_length = 0;
  1770   for (uint next = 0; next < cg_length; ++next) {
  1771     int ni = cg_worklist.at(next);
  1772     PointsToNode* ptn = ptnode_adr(ni);
  1773     PointsToNode::NodeType nt = ptn->node_type();
  1774     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
  1775       if (ptn->edge_count() == 0) {
  1776         // No values were found. Assume the value was set
  1777         // outside this method - add edge to phantom object.
  1778         add_pointsto_edge(ni, _phantom_object);
  1783   // 7. Remove deferred edges from the graph.
  1784   for (uint next = 0; next < cg_length; ++next) {
  1785     int ni = cg_worklist.at(next);
  1786     PointsToNode* ptn = ptnode_adr(ni);
  1787     PointsToNode::NodeType nt = ptn->node_type();
  1788     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
  1789       remove_deferred(ni, &worklist, &visited);
  1793   // 8. Adjust escape state of nonescaping objects.
  1794   for (uint next = 0; next < addp_length; ++next) {
  1795     Node* n = addp_worklist.at(next);
  1796     adjust_escape_state(n);
  1799   // push all NoEscape nodes on the worklist
  1800   worklist.clear();
  1801   for( uint next = 0; next < cg_length; ++next ) {
  1802     int nk = cg_worklist.at(next);
  1803     if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape &&
  1804         !is_null_ptr(nk))
  1805       worklist.push(nk);
  1808   alloc_worklist.clear();
  1809   // Propagate scalar_replaceable value.
  1810   while(worklist.length() > 0) {
  1811     uint nk = worklist.pop();
  1812     PointsToNode* ptn = ptnode_adr(nk);
  1813     Node* n = ptn->_node;
  1814     bool scalar_replaceable = ptn->scalar_replaceable();
  1815     if (n->is_Allocate() && scalar_replaceable) {
  1816       // Push scalar replaceable allocations on alloc_worklist
  1817       // for processing in split_unique_types(). Note,
  1818       // following code may change scalar_replaceable value.
  1819       alloc_worklist.append(n);
  1821     uint e_cnt = ptn->edge_count();
  1822     for (uint ei = 0; ei < e_cnt; ei++) {
  1823       uint npi = ptn->edge_target(ei);
  1824       if (is_null_ptr(npi))
  1825         continue;
  1826       PointsToNode *np = ptnode_adr(npi);
  1827       if (np->escape_state() < PointsToNode::NoEscape) {
  1828         set_escape_state(npi, PointsToNode::NoEscape);
  1829         if (!scalar_replaceable) {
  1830           np->set_scalar_replaceable(false);
  1832         worklist.push(npi);
  1833       } else if (np->scalar_replaceable() && !scalar_replaceable) {
  1834         np->set_scalar_replaceable(false);
  1835         worklist.push(npi);
  1840   _collecting = false;
  1841   assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
  1843   assert(ptnode_adr(_oop_null)->escape_state() == PointsToNode::NoEscape &&
  1844          ptnode_adr(_oop_null)->edge_count() == 0, "sanity");
  1845   if (UseCompressedOops) {
  1846     assert(ptnode_adr(_noop_null)->escape_state() == PointsToNode::NoEscape &&
  1847            ptnode_adr(_noop_null)->edge_count() == 0, "sanity");
  1850   if (EliminateLocks && has_non_escaping_obj) {
  1851     // Mark locks before changing ideal graph.
  1852     int cnt = C->macro_count();
  1853     for( int i=0; i < cnt; i++ ) {
  1854       Node *n = C->macro_node(i);
  1855       if (n->is_AbstractLock()) { // Lock and Unlock nodes
  1856         AbstractLockNode* alock = n->as_AbstractLock();
  1857         if (!alock->is_non_esc_obj()) {
  1858           PointsToNode::EscapeState es = escape_state(alock->obj_node());
  1859           assert(es != PointsToNode::UnknownEscape, "should know");
  1860           if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
  1861             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
  1862             // The lock could be marked eliminated by lock coarsening
  1863             // code during first IGVN before EA. Replace coarsened flag
  1864             // to eliminate all associated locks/unlocks.
  1865             alock->set_non_esc_obj();
  1872   if (OptimizePtrCompare && has_non_escaping_obj) {
  1873     // Add ConI(#CC_GT) and ConI(#CC_EQ).
  1874     _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
  1875     _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
  1876     // Optimize objects compare.
  1877     while (ptr_cmp_worklist.length() != 0) {
  1878       Node *n = ptr_cmp_worklist.pop();
  1879       Node *res = optimize_ptr_compare(n);
  1880       if (res != NULL) {
  1881 #ifndef PRODUCT
  1882         if (PrintOptimizePtrCompare) {
  1883           tty->print_cr("++++ Replaced: %d %s(%d,%d) --> %s", n->_idx, (n->Opcode() == Op_CmpP ? "CmpP" : "CmpN"), n->in(1)->_idx, n->in(2)->_idx, (res == _pcmp_eq ? "EQ" : "NotEQ"));
  1884           if (Verbose) {
  1885             n->dump(1);
  1888 #endif
  1889         _igvn->replace_node(n, res);
  1892     // cleanup
  1893     if (_pcmp_neq->outcnt() == 0)
  1894       igvn->hash_delete(_pcmp_neq);
  1895     if (_pcmp_eq->outcnt()  == 0)
  1896       igvn->hash_delete(_pcmp_eq);
  1899   // For MemBarStoreStore nodes added in library_call.cpp, check
  1900   // escape status of associated AllocateNode and optimize out
  1901   // MemBarStoreStore node if the allocated object never escapes.
  1902   while (storestore_worklist.length() != 0) {
  1903     Node *n = storestore_worklist.pop();
  1904     MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
  1905     Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
  1906     assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
  1907     PointsToNode::EscapeState es = ptnode_adr(alloc->_idx)->escape_state();
  1908     if (es == PointsToNode::NoEscape || es == PointsToNode::ArgEscape) {
  1909       MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
  1910       mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
  1911       mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
  1913       _igvn->register_new_node_with_optimizer(mb);
  1914       _igvn->replace_node(storestore, mb);
  1918 #ifndef PRODUCT
  1919   if (PrintEscapeAnalysis) {
  1920     dump(); // Dump ConnectionGraph
  1922 #endif
  1924   bool has_scalar_replaceable_candidates = false;
  1925   alloc_length = alloc_worklist.length();
  1926   for (uint next = 0; next < alloc_length; ++next) {
  1927     Node* n = alloc_worklist.at(next);
  1928     PointsToNode* ptn = ptnode_adr(n->_idx);
  1929     assert(ptn->escape_state() == PointsToNode::NoEscape, "sanity");
  1930     if (ptn->scalar_replaceable()) {
  1931       has_scalar_replaceable_candidates = true;
  1932       break;
  1936   if ( has_scalar_replaceable_candidates &&
  1937        C->AliasLevel() >= 3 && EliminateAllocations ) {
  1939     // Now use the escape information to create unique types for
  1940     // scalar replaceable objects.
  1941     split_unique_types(alloc_worklist);
  1943     if (C->failing())  return false;
  1945     C->print_method("After Escape Analysis", 2);
  1947 #ifdef ASSERT
  1948   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
  1949     tty->print("=== No allocations eliminated for ");
  1950     C->method()->print_short_name();
  1951     if(!EliminateAllocations) {
  1952       tty->print(" since EliminateAllocations is off ===");
  1953     } else if(!has_scalar_replaceable_candidates) {
  1954       tty->print(" since there are no scalar replaceable candidates ===");
  1955     } else if(C->AliasLevel() < 3) {
  1956       tty->print(" since AliasLevel < 3 ===");
  1958     tty->cr();
  1959 #endif
  1961   return has_non_escaping_obj;
  1964 // Find fields initializing values for allocations.
  1965 void ConnectionGraph::find_init_values(Node* alloc, VectorSet* visited, PhaseTransform* phase) {
  1966   assert(alloc->is_Allocate(), "Should be called for Allocate nodes only");
  1967   PointsToNode* pta = ptnode_adr(alloc->_idx);
  1968   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
  1969   InitializeNode* ini = alloc->as_Allocate()->initialization();
  1971   Compile* C = _compile;
  1972   visited->Reset();
  1973   // Check if a oop field's initializing value is recorded and add
  1974   // a corresponding NULL field's value if it is not recorded.
  1975   // Connection Graph does not record a default initialization by NULL
  1976   // captured by Initialize node.
  1977   //
  1978   uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
  1979   uint ae_cnt = pta->edge_count();
  1980   bool visited_bottom_offset = false;
  1981   for (uint ei = 0; ei < ae_cnt; ei++) {
  1982     uint nidx = pta->edge_target(ei); // Field (AddP)
  1983     PointsToNode* ptn = ptnode_adr(nidx);
  1984     assert(ptn->_node->is_AddP(), "Should be AddP nodes only");
  1985     int offset = ptn->offset();
  1986     if (offset == Type::OffsetBot) {
  1987       if (!visited_bottom_offset) {
  1988         visited_bottom_offset = true;
  1989         // Check only oop fields.
  1990         const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
  1991         if (!adr_type->isa_aryptr() ||
  1992             (adr_type->isa_aryptr()->klass() == NULL) ||
  1993              adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
  1994           // OffsetBot is used to reference array's element,
  1995           // always add reference to NULL since we don't
  1996           // known which element is referenced.
  1997           add_edge_from_fields(alloc->_idx, null_idx, offset);
  2000     } else if (offset != oopDesc::klass_offset_in_bytes() &&
  2001                !visited->test_set(offset)) {
  2003       // Check only oop fields.
  2004       const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
  2005       BasicType basic_field_type = T_INT;
  2006       if (adr_type->isa_instptr()) {
  2007         ciField* field = C->alias_type(adr_type->isa_instptr())->field();
  2008         if (field != NULL) {
  2009           basic_field_type = field->layout_type();
  2010         } else {
  2011           // Ignore non field load (for example, klass load)
  2013       } else if (adr_type->isa_aryptr()) {
  2014         if (offset != arrayOopDesc::length_offset_in_bytes()) {
  2015           const Type* elemtype = adr_type->isa_aryptr()->elem();
  2016           basic_field_type = elemtype->array_element_basic_type();
  2017         } else {
  2018           // Ignore array length load
  2020 #ifdef ASSERT
  2021       } else {
  2022         // Raw pointers are used for initializing stores so skip it
  2023         // since it should be recorded already
  2024         Node* base = get_addp_base(ptn->_node);
  2025         assert(adr_type->isa_rawptr() && base->is_Proj() &&
  2026                (base->in(0) == alloc),"unexpected pointer type");
  2027 #endif
  2029       if (basic_field_type == T_OBJECT ||
  2030           basic_field_type == T_NARROWOOP ||
  2031           basic_field_type == T_ARRAY) {
  2032         Node* value = NULL;
  2033         if (ini != NULL) {
  2034           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
  2035           Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
  2036           if (store != NULL && store->is_Store()) {
  2037             value = store->in(MemNode::ValueIn);
  2038           } else if (ptn->edge_count() > 0) { // Are there oop stores?
  2039             // Check for a store which follows allocation without branches.
  2040             // For example, a volatile field store is not collected
  2041             // by Initialize node. TODO: it would be nice to use idom() here.
  2042             //
  2043             // Search all references to the same field which use different
  2044             // AddP nodes, for example, in the next case:
  2045             //
  2046             //    Point p[] = new Point[1];
  2047             //    if ( x ) { p[0] = new Point(); p[0].x = x; }
  2048             //    if ( p[0] != null ) { y = p[0].x; } // has CastPP
  2049             //
  2050             for (uint next = ei; (next < ae_cnt) && (value == NULL); next++) {
  2051               uint fpi = pta->edge_target(next); // Field (AddP)
  2052               PointsToNode *ptf = ptnode_adr(fpi);
  2053               if (ptf->offset() == offset) {
  2054                 Node* nf = ptf->_node;
  2055                 for (DUIterator_Fast imax, i = nf->fast_outs(imax); i < imax; i++) {
  2056                   store = nf->fast_out(i);
  2057                   if (store->is_Store() && store->in(0) != NULL) {
  2058                     Node* ctrl = store->in(0);
  2059                     while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
  2060                             ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
  2061                             ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
  2062                        ctrl = ctrl->in(0);
  2064                     if (ctrl == ini || ctrl == alloc) {
  2065                       value = store->in(MemNode::ValueIn);
  2066                       break;
  2074         if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
  2075           // A field's initializing value was not recorded. Add NULL.
  2076           add_edge_from_fields(alloc->_idx, null_idx, offset);
  2083 // Adjust escape state after Connection Graph is built.
  2084 void ConnectionGraph::adjust_escape_state(Node* n) {
  2085   PointsToNode* ptn = ptnode_adr(n->_idx);
  2086   assert(n->is_AddP(), "Should be called for AddP nodes only");
  2087   // Search for objects which are not scalar replaceable
  2088   // and mark them to propagate the state to referenced objects.
  2089   //
  2091   int offset = ptn->offset();
  2092   Node* base = get_addp_base(n);
  2093   VectorSet* ptset = PointsTo(base);
  2094   int ptset_size = ptset->Size();
  2096   // An object is not scalar replaceable if the field which may point
  2097   // to it has unknown offset (unknown element of an array of objects).
  2098   //
  2100   if (offset == Type::OffsetBot) {
  2101     uint e_cnt = ptn->edge_count();
  2102     for (uint ei = 0; ei < e_cnt; ei++) {
  2103       uint npi = ptn->edge_target(ei);
  2104       ptnode_adr(npi)->set_scalar_replaceable(false);
  2108   // Currently an object is not scalar replaceable if a LoadStore node
  2109   // access its field since the field value is unknown after it.
  2110   //
  2111   bool has_LoadStore = false;
  2112   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  2113     Node *use = n->fast_out(i);
  2114     if (use->is_LoadStore()) {
  2115       has_LoadStore = true;
  2116       break;
  2119   // An object is not scalar replaceable if the address points
  2120   // to unknown field (unknown element for arrays, offset is OffsetBot).
  2121   //
  2122   // Or the address may point to more then one object. This may produce
  2123   // the false positive result (set not scalar replaceable)
  2124   // since the flow-insensitive escape analysis can't separate
  2125   // the case when stores overwrite the field's value from the case
  2126   // when stores happened on different control branches.
  2127   //
  2128   // Note: it will disable scalar replacement in some cases:
  2129   //
  2130   //    Point p[] = new Point[1];
  2131   //    p[0] = new Point(); // Will be not scalar replaced
  2132   //
  2133   // but it will save us from incorrect optimizations in next cases:
  2134   //
  2135   //    Point p[] = new Point[1];
  2136   //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
  2137   //
  2138   if (ptset_size > 1 || ptset_size != 0 &&
  2139       (has_LoadStore || offset == Type::OffsetBot)) {
  2140     for( VectorSetI j(ptset); j.test(); ++j ) {
  2141       ptnode_adr(j.elem)->set_scalar_replaceable(false);
  2146 // Propagate escape states to referenced nodes.
  2147 bool ConnectionGraph::propagate_escape_state(GrowableArray<int>* cg_worklist,
  2148                                              GrowableArray<uint>* worklist,
  2149                                              PointsToNode::EscapeState esc_state) {
  2150   bool has_java_obj = false;
  2152   // push all nodes with the same escape state on the worklist
  2153   uint cg_length = cg_worklist->length();
  2154   for (uint next = 0; next < cg_length; ++next) {
  2155     int nk = cg_worklist->at(next);
  2156     if (ptnode_adr(nk)->escape_state() == esc_state)
  2157       worklist->push(nk);
  2159   // mark all reachable nodes
  2160   while (worklist->length() > 0) {
  2161     int pt = worklist->pop();
  2162     PointsToNode* ptn = ptnode_adr(pt);
  2163     if (ptn->node_type() == PointsToNode::JavaObject &&
  2164         !is_null_ptr(pt)) {
  2165       has_java_obj = true;
  2166       if (esc_state > PointsToNode::NoEscape) {
  2167         // fields values are unknown if object escapes
  2168         add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
  2171     uint e_cnt = ptn->edge_count();
  2172     for (uint ei = 0; ei < e_cnt; ei++) {
  2173       uint npi = ptn->edge_target(ei);
  2174       if (is_null_ptr(npi))
  2175         continue;
  2176       PointsToNode *np = ptnode_adr(npi);
  2177       if (np->escape_state() < esc_state) {
  2178         set_escape_state(npi, esc_state);
  2179         worklist->push(npi);
  2183   // Has not escaping java objects
  2184   return has_java_obj && (esc_state < PointsToNode::GlobalEscape);
  2187 // Optimize objects compare.
  2188 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
  2189   assert(OptimizePtrCompare, "sanity");
  2190   // Clone returned Set since PointsTo() returns pointer
  2191   // to the same structure ConnectionGraph.pt_ptset.
  2192   VectorSet ptset1 = *PointsTo(n->in(1));
  2193   VectorSet ptset2 = *PointsTo(n->in(2));
  2195   // Check simple cases first.
  2196   if (ptset1.Size() == 1) {
  2197     uint pt1 = ptset1.getelem();
  2198     PointsToNode* ptn1 = ptnode_adr(pt1);
  2199     if (ptn1->escape_state() == PointsToNode::NoEscape) {
  2200       if (ptset2.Size() == 1 && ptset2.getelem() == pt1) {
  2201         // Comparing the same not escaping object.
  2202         return _pcmp_eq;
  2204       Node* obj = ptn1->_node;
  2205       // Comparing not escaping allocation.
  2206       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
  2207           !ptset2.test(pt1)) {
  2208         return _pcmp_neq; // This includes nullness check.
  2211   } else if (ptset2.Size() == 1) {
  2212     uint pt2 = ptset2.getelem();
  2213     PointsToNode* ptn2 = ptnode_adr(pt2);
  2214     if (ptn2->escape_state() == PointsToNode::NoEscape) {
  2215       Node* obj = ptn2->_node;
  2216       // Comparing not escaping allocation.
  2217       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
  2218           !ptset1.test(pt2)) {
  2219         return _pcmp_neq; // This includes nullness check.
  2224   if (!ptset1.disjoint(ptset2)) {
  2225     return NULL; // Sets are not disjoint
  2228   // Sets are disjoint.
  2229   bool set1_has_unknown_ptr = ptset1.test(_phantom_object) != 0;
  2230   bool set2_has_unknown_ptr = ptset2.test(_phantom_object) != 0;
  2231   bool set1_has_null_ptr   = (ptset1.test(_oop_null) | ptset1.test(_noop_null)) != 0;
  2232   bool set2_has_null_ptr   = (ptset2.test(_oop_null) | ptset2.test(_noop_null)) != 0;
  2234   if (set1_has_unknown_ptr && set2_has_null_ptr ||
  2235       set2_has_unknown_ptr && set1_has_null_ptr) {
  2236     // Check nullness of unknown object.
  2237     return NULL;
  2240   // Disjointness by itself is not sufficient since
  2241   // alias analysis is not complete for escaped objects.
  2242   // Disjoint sets are definitely unrelated only when
  2243   // at least one set has only not escaping objects.
  2244   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
  2245     bool has_only_non_escaping_alloc = true;
  2246     for (VectorSetI i(&ptset1); i.test(); ++i) {
  2247       uint pt = i.elem;
  2248       PointsToNode* ptn = ptnode_adr(pt);
  2249       Node* obj = ptn->_node;
  2250       if (ptn->escape_state() != PointsToNode::NoEscape ||
  2251           !(obj->is_Allocate() || obj->is_CallStaticJava())) {
  2252         has_only_non_escaping_alloc = false;
  2253         break;
  2256     if (has_only_non_escaping_alloc) {
  2257       return _pcmp_neq;
  2260   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
  2261     bool has_only_non_escaping_alloc = true;
  2262     for (VectorSetI i(&ptset2); i.test(); ++i) {
  2263       uint pt = i.elem;
  2264       PointsToNode* ptn = ptnode_adr(pt);
  2265       Node* obj = ptn->_node;
  2266       if (ptn->escape_state() != PointsToNode::NoEscape ||
  2267           !(obj->is_Allocate() || obj->is_CallStaticJava())) {
  2268         has_only_non_escaping_alloc = false;
  2269         break;
  2272     if (has_only_non_escaping_alloc) {
  2273       return _pcmp_neq;
  2276   return NULL;
  2279 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
  2280     bool is_arraycopy = false;
  2281     switch (call->Opcode()) {
  2282 #ifdef ASSERT
  2283     case Op_Allocate:
  2284     case Op_AllocateArray:
  2285     case Op_Lock:
  2286     case Op_Unlock:
  2287       assert(false, "should be done already");
  2288       break;
  2289 #endif
  2290     case Op_CallLeafNoFP:
  2291       is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
  2292                       strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
  2293       // fall through
  2294     case Op_CallLeaf:
  2296       // Stub calls, objects do not escape but they are not scale replaceable.
  2297       // Adjust escape state for outgoing arguments.
  2298       const TypeTuple * d = call->tf()->domain();
  2299       bool src_has_oops = false;
  2300       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2301         const Type* at = d->field_at(i);
  2302         Node *arg = call->in(i)->uncast();
  2303         const Type *aat = phase->type(arg);
  2304         PointsToNode::EscapeState arg_esc = ptnode_adr(arg->_idx)->escape_state();
  2305         if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
  2306             (is_arraycopy || arg_esc < PointsToNode::ArgEscape)) {
  2307 #ifdef ASSERT
  2308           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
  2309                  aat->isa_ptr() != NULL, "expecting an Ptr");
  2310           if (!(is_arraycopy ||
  2311                 call->as_CallLeaf()->_name != NULL &&
  2312                 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
  2313                  strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
  2314           ) {
  2315             call->dump();
  2316             assert(false, "EA: unexpected CallLeaf");
  2318 #endif
  2319           if (arg_esc < PointsToNode::ArgEscape) {
  2320             set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  2321             Node* arg_base = arg;
  2322             if (arg->is_AddP()) {
  2323               //
  2324               // The inline_native_clone() case when the arraycopy stub is called
  2325               // after the allocation before Initialize and CheckCastPP nodes.
  2326               // Or normal arraycopy for object arrays case.
  2327               //
  2328               // Set AddP's base (Allocate) as not scalar replaceable since
  2329               // pointer to the base (with offset) is passed as argument.
  2330               //
  2331               arg_base = get_addp_base(arg);
  2332               set_escape_state(arg_base->_idx, PointsToNode::ArgEscape);
  2336           bool arg_has_oops = aat->isa_oopptr() &&
  2337                               (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
  2338                                (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
  2339           if (i == TypeFunc::Parms) {
  2340             src_has_oops = arg_has_oops;
  2342           //
  2343           // src or dst could be j.l.Object when other is basic type array:
  2344           //
  2345           //   arraycopy(char[],0,Object*,0,size);
  2346           //   arraycopy(Object*,0,char[],0,size);
  2347           //
  2348           // Do nothing special in such cases.
  2349           //
  2350           if (is_arraycopy && (i > TypeFunc::Parms) &&
  2351               src_has_oops && arg_has_oops) {
  2352             // Destination object's fields reference an unknown object.
  2353             Node* arg_base = arg;
  2354             if (arg->is_AddP()) {
  2355               arg_base = get_addp_base(arg);
  2357             for (VectorSetI s(PointsTo(arg_base)); s.test(); ++s) {
  2358               uint ps = s.elem;
  2359               set_escape_state(ps, PointsToNode::ArgEscape);
  2360               add_edge_from_fields(ps, _phantom_object, Type::OffsetBot);
  2362             // Conservatively all values in source object fields globally escape
  2363             // since we don't know if values in destination object fields
  2364             // escape (it could be traced but it is too expensive).
  2365             Node* src = call->in(TypeFunc::Parms)->uncast();
  2366             Node* src_base = src;
  2367             if (src->is_AddP()) {
  2368               src_base  = get_addp_base(src);
  2370             for (VectorSetI s(PointsTo(src_base)); s.test(); ++s) {
  2371               uint ps = s.elem;
  2372               set_escape_state(ps, PointsToNode::ArgEscape);
  2373               // Use OffsetTop to indicate fields global escape.
  2374               add_edge_from_fields(ps, _phantom_object, Type::OffsetTop);
  2379       break;
  2382     case Op_CallStaticJava:
  2383     // For a static call, we know exactly what method is being called.
  2384     // Use bytecode estimator to record the call's escape affects
  2386       ciMethod *meth = call->as_CallJava()->method();
  2387       BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
  2388       // fall-through if not a Java method or no analyzer information
  2389       if (call_analyzer != NULL) {
  2390         const TypeTuple * d = call->tf()->domain();
  2391         bool copy_dependencies = false;
  2392         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2393           const Type* at = d->field_at(i);
  2394           int k = i - TypeFunc::Parms;
  2395           Node *arg = call->in(i)->uncast();
  2397           if (at->isa_oopptr() != NULL &&
  2398               ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
  2400             bool global_escapes = false;
  2401             bool fields_escapes = false;
  2402             if (!call_analyzer->is_arg_stack(k)) {
  2403               // The argument global escapes, mark everything it could point to
  2404               set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  2405               global_escapes = true;
  2406             } else {
  2407               if (!call_analyzer->is_arg_local(k)) {
  2408                 // The argument itself doesn't escape, but any fields might
  2409                 fields_escapes = true;
  2411               set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  2412               copy_dependencies = true;
  2415             for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
  2416               uint pt = j.elem;
  2417               if (global_escapes) {
  2418                 // The argument global escapes, mark everything it could point to
  2419                 set_escape_state(pt, PointsToNode::GlobalEscape);
  2420                 add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
  2421               } else {
  2422                 set_escape_state(pt, PointsToNode::ArgEscape);
  2423                 if (fields_escapes) {
  2424                   // The argument itself doesn't escape, but any fields might.
  2425                   // Use OffsetTop to indicate such case.
  2426                   add_edge_from_fields(pt, _phantom_object, Type::OffsetTop);
  2432         if (copy_dependencies)
  2433           call_analyzer->copy_dependencies(_compile->dependencies());
  2434         break;
  2438     default:
  2439     // Fall-through here if not a Java method or no analyzer information
  2440     // or some other type of call, assume the worst case: all arguments
  2441     // globally escape.
  2443       // adjust escape state for  outgoing arguments
  2444       const TypeTuple * d = call->tf()->domain();
  2445       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2446         const Type* at = d->field_at(i);
  2447         if (at->isa_oopptr() != NULL) {
  2448           Node *arg = call->in(i)->uncast();
  2449           set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  2450           for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
  2451             uint pt = j.elem;
  2452             set_escape_state(pt, PointsToNode::GlobalEscape);
  2453             add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
  2460 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
  2461   CallNode   *call = resproj->in(0)->as_Call();
  2462   uint    call_idx = call->_idx;
  2463   uint resproj_idx = resproj->_idx;
  2465   switch (call->Opcode()) {
  2466     case Op_Allocate:
  2468       Node *k = call->in(AllocateNode::KlassNode);
  2469       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2470       assert(kt != NULL, "TypeKlassPtr  required.");
  2471       ciKlass* cik = kt->klass();
  2473       PointsToNode::EscapeState es;
  2474       uint edge_to;
  2475       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
  2476          !cik->is_instance_klass() || // StressReflectiveCode
  2477           cik->as_instance_klass()->has_finalizer()) {
  2478         es = PointsToNode::GlobalEscape;
  2479         edge_to = _phantom_object; // Could not be worse
  2480       } else {
  2481         es = PointsToNode::NoEscape;
  2482         edge_to = call_idx;
  2483         assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
  2485       set_escape_state(call_idx, es);
  2486       add_pointsto_edge(resproj_idx, edge_to);
  2487       _processed.set(resproj_idx);
  2488       break;
  2491     case Op_AllocateArray:
  2494       Node *k = call->in(AllocateNode::KlassNode);
  2495       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2496       assert(kt != NULL, "TypeKlassPtr  required.");
  2497       ciKlass* cik = kt->klass();
  2499       PointsToNode::EscapeState es;
  2500       uint edge_to;
  2501       if (!cik->is_array_klass()) { // StressReflectiveCode
  2502         es = PointsToNode::GlobalEscape;
  2503         edge_to = _phantom_object;
  2504       } else {
  2505         es = PointsToNode::NoEscape;
  2506         edge_to = call_idx;
  2507         assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
  2508         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
  2509         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
  2510           // Not scalar replaceable if the length is not constant or too big.
  2511           ptnode_adr(call_idx)->set_scalar_replaceable(false);
  2514       set_escape_state(call_idx, es);
  2515       add_pointsto_edge(resproj_idx, edge_to);
  2516       _processed.set(resproj_idx);
  2517       break;
  2520     case Op_CallStaticJava:
  2521     // For a static call, we know exactly what method is being called.
  2522     // Use bytecode estimator to record whether the call's return value escapes
  2524       bool done = true;
  2525       const TypeTuple *r = call->tf()->range();
  2526       const Type* ret_type = NULL;
  2528       if (r->cnt() > TypeFunc::Parms)
  2529         ret_type = r->field_at(TypeFunc::Parms);
  2531       // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2532       //        _multianewarray functions return a TypeRawPtr.
  2533       if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
  2534         _processed.set(resproj_idx);
  2535         break;  // doesn't return a pointer type
  2537       ciMethod *meth = call->as_CallJava()->method();
  2538       const TypeTuple * d = call->tf()->domain();
  2539       if (meth == NULL) {
  2540         // not a Java method, assume global escape
  2541         set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2542         add_pointsto_edge(resproj_idx, _phantom_object);
  2543       } else {
  2544         BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
  2545         bool copy_dependencies = false;
  2547         if (call_analyzer->is_return_allocated()) {
  2548           // Returns a newly allocated unescaped object, simply
  2549           // update dependency information.
  2550           // Mark it as NoEscape so that objects referenced by
  2551           // it's fields will be marked as NoEscape at least.
  2552           set_escape_state(call_idx, PointsToNode::NoEscape);
  2553           ptnode_adr(call_idx)->set_scalar_replaceable(false);
  2554           // Fields values are unknown
  2555           add_edge_from_fields(call_idx, _phantom_object, Type::OffsetBot);
  2556           add_pointsto_edge(resproj_idx, call_idx);
  2557           copy_dependencies = true;
  2558         } else {
  2559           // determine whether any arguments are returned
  2560           set_escape_state(call_idx, PointsToNode::ArgEscape);
  2561           bool ret_arg = false;
  2562           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2563             const Type* at = d->field_at(i);
  2564             if (at->isa_oopptr() != NULL) {
  2565               Node *arg = call->in(i)->uncast();
  2567               if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
  2568                 ret_arg = true;
  2569                 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
  2570                 if (arg_esp->node_type() == PointsToNode::UnknownType)
  2571                   done = false;
  2572                 else if (arg_esp->node_type() == PointsToNode::JavaObject)
  2573                   add_pointsto_edge(resproj_idx, arg->_idx);
  2574                 else
  2575                   add_deferred_edge(resproj_idx, arg->_idx);
  2579           if (done) {
  2580             copy_dependencies = true;
  2581             // is_return_local() is true when only arguments are returned.
  2582             if (!ret_arg || !call_analyzer->is_return_local()) {
  2583               // Returns unknown object.
  2584               add_pointsto_edge(resproj_idx, _phantom_object);
  2588         if (copy_dependencies)
  2589           call_analyzer->copy_dependencies(_compile->dependencies());
  2591       if (done)
  2592         _processed.set(resproj_idx);
  2593       break;
  2596     default:
  2597     // Some other type of call, assume the worst case that the
  2598     // returned value, if any, globally escapes.
  2600       const TypeTuple *r = call->tf()->range();
  2601       if (r->cnt() > TypeFunc::Parms) {
  2602         const Type* ret_type = r->field_at(TypeFunc::Parms);
  2604         // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2605         //        _multianewarray functions return a TypeRawPtr.
  2606         if (ret_type->isa_ptr() != NULL) {
  2607           set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2608           add_pointsto_edge(resproj_idx, _phantom_object);
  2611       _processed.set(resproj_idx);
  2616 // Populate Connection Graph with Ideal nodes and create simple
  2617 // connection graph edges (do not need to check the node_type of inputs
  2618 // or to call PointsTo() to walk the connection graph).
  2619 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
  2620   if (_processed.test(n->_idx))
  2621     return; // No need to redefine node's state.
  2623   if (n->is_Call()) {
  2624     // Arguments to allocation and locking don't escape.
  2625     if (n->is_Allocate()) {
  2626       add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
  2627       record_for_optimizer(n);
  2628     } else if (n->is_Lock() || n->is_Unlock()) {
  2629       // Put Lock and Unlock nodes on IGVN worklist to process them during
  2630       // the first IGVN optimization when escape information is still available.
  2631       record_for_optimizer(n);
  2632       _processed.set(n->_idx);
  2633     } else {
  2634       // Don't mark as processed since call's arguments have to be processed.
  2635       PointsToNode::NodeType nt = PointsToNode::UnknownType;
  2636       PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
  2638       // Check if a call returns an object.
  2639       const TypeTuple *r = n->as_Call()->tf()->range();
  2640       if (r->cnt() > TypeFunc::Parms &&
  2641           r->field_at(TypeFunc::Parms)->isa_ptr() &&
  2642           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
  2643         nt = PointsToNode::JavaObject;
  2644         if (!n->is_CallStaticJava()) {
  2645           // Since the called mathod is statically unknown assume
  2646           // the worst case that the returned value globally escapes.
  2647           es = PointsToNode::GlobalEscape;
  2650       add_node(n, nt, es, false);
  2652     return;
  2655   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
  2656   // ThreadLocal has RawPrt type.
  2657   switch (n->Opcode()) {
  2658     case Op_AddP:
  2660       add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
  2661       break;
  2663     case Op_CastX2P:
  2664     { // "Unsafe" memory access.
  2665       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2666       break;
  2668     case Op_CastPP:
  2669     case Op_CheckCastPP:
  2670     case Op_EncodeP:
  2671     case Op_DecodeN:
  2673       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2674       int ti = n->in(1)->_idx;
  2675       PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2676       if (nt == PointsToNode::UnknownType) {
  2677         _delayed_worklist.push(n); // Process it later.
  2678         break;
  2679       } else if (nt == PointsToNode::JavaObject) {
  2680         add_pointsto_edge(n->_idx, ti);
  2681       } else {
  2682         add_deferred_edge(n->_idx, ti);
  2684       _processed.set(n->_idx);
  2685       break;
  2687     case Op_ConP:
  2689       // assume all pointer constants globally escape except for null
  2690       PointsToNode::EscapeState es;
  2691       if (phase->type(n) == TypePtr::NULL_PTR)
  2692         es = PointsToNode::NoEscape;
  2693       else
  2694         es = PointsToNode::GlobalEscape;
  2696       add_node(n, PointsToNode::JavaObject, es, true);
  2697       break;
  2699     case Op_ConN:
  2701       // assume all narrow oop constants globally escape except for null
  2702       PointsToNode::EscapeState es;
  2703       if (phase->type(n) == TypeNarrowOop::NULL_PTR)
  2704         es = PointsToNode::NoEscape;
  2705       else
  2706         es = PointsToNode::GlobalEscape;
  2708       add_node(n, PointsToNode::JavaObject, es, true);
  2709       break;
  2711     case Op_CreateEx:
  2713       // assume that all exception objects globally escape
  2714       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2715       break;
  2717     case Op_LoadKlass:
  2718     case Op_LoadNKlass:
  2720       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2721       break;
  2723     case Op_LoadP:
  2724     case Op_LoadN:
  2726       const Type *t = phase->type(n);
  2727       if (t->make_ptr() == NULL) {
  2728         _processed.set(n->_idx);
  2729         return;
  2731       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2732       break;
  2734     case Op_Parm:
  2736       _processed.set(n->_idx); // No need to redefine it state.
  2737       uint con = n->as_Proj()->_con;
  2738       if (con < TypeFunc::Parms)
  2739         return;
  2740       const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
  2741       if (t->isa_ptr() == NULL)
  2742         return;
  2743       // We have to assume all input parameters globally escape
  2744       // (Note: passing 'false' since _processed is already set).
  2745       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
  2746       break;
  2748     case Op_PartialSubtypeCheck:
  2749     { // Produces Null or notNull and is used in CmpP.
  2750       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
  2751       break;
  2753     case Op_Phi:
  2755       const Type *t = n->as_Phi()->type();
  2756       if (t->make_ptr() == NULL) {
  2757         // nothing to do if not an oop or narrow oop
  2758         _processed.set(n->_idx);
  2759         return;
  2761       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2762       uint i;
  2763       for (i = 1; i < n->req() ; i++) {
  2764         Node* in = n->in(i);
  2765         if (in == NULL)
  2766           continue;  // ignore NULL
  2767         in = in->uncast();
  2768         if (in->is_top() || in == n)
  2769           continue;  // ignore top or inputs which go back this node
  2770         int ti = in->_idx;
  2771         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2772         if (nt == PointsToNode::UnknownType) {
  2773           break;
  2774         } else if (nt == PointsToNode::JavaObject) {
  2775           add_pointsto_edge(n->_idx, ti);
  2776         } else {
  2777           add_deferred_edge(n->_idx, ti);
  2780       if (i >= n->req())
  2781         _processed.set(n->_idx);
  2782       else
  2783         _delayed_worklist.push(n);
  2784       break;
  2786     case Op_Proj:
  2788       // we are only interested in the oop result projection from a call
  2789       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  2790         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  2791         assert(r->cnt() > TypeFunc::Parms, "sanity");
  2792         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  2793           add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2794           int ti = n->in(0)->_idx;
  2795           // The call may not be registered yet (since not all its inputs are registered)
  2796           // if this is the projection from backbranch edge of Phi.
  2797           if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
  2798             process_call_result(n->as_Proj(), phase);
  2800           if (!_processed.test(n->_idx)) {
  2801             // The call's result may need to be processed later if the call
  2802             // returns it's argument and the argument is not processed yet.
  2803             _delayed_worklist.push(n);
  2805           break;
  2808       _processed.set(n->_idx);
  2809       break;
  2811     case Op_Return:
  2813       if( n->req() > TypeFunc::Parms &&
  2814           phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  2815         // Treat Return value as LocalVar with GlobalEscape escape state.
  2816         add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
  2817         int ti = n->in(TypeFunc::Parms)->_idx;
  2818         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2819         if (nt == PointsToNode::UnknownType) {
  2820           _delayed_worklist.push(n); // Process it later.
  2821           break;
  2822         } else if (nt == PointsToNode::JavaObject) {
  2823           add_pointsto_edge(n->_idx, ti);
  2824         } else {
  2825           add_deferred_edge(n->_idx, ti);
  2828       _processed.set(n->_idx);
  2829       break;
  2831     case Op_StoreP:
  2832     case Op_StoreN:
  2834       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2835       adr_type = adr_type->make_ptr();
  2836       if (adr_type->isa_oopptr()) {
  2837         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2838       } else {
  2839         Node* adr = n->in(MemNode::Address);
  2840         if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
  2841             adr->in(AddPNode::Address)->is_Proj() &&
  2842             adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
  2843           add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2844           // We are computing a raw address for a store captured
  2845           // by an Initialize compute an appropriate address type.
  2846           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
  2847           assert(offs != Type::OffsetBot, "offset must be a constant");
  2848         } else {
  2849           _processed.set(n->_idx);
  2850           return;
  2853       break;
  2855     case Op_StorePConditional:
  2856     case Op_CompareAndSwapP:
  2857     case Op_CompareAndSwapN:
  2859       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2860       adr_type = adr_type->make_ptr();
  2861       if (adr_type->isa_oopptr()) {
  2862         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2863       } else {
  2864         _processed.set(n->_idx);
  2865         return;
  2867       break;
  2869     case Op_AryEq:
  2870     case Op_StrComp:
  2871     case Op_StrEquals:
  2872     case Op_StrIndexOf:
  2874       // char[] arrays passed to string intrinsics are not scalar replaceable.
  2875       add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2876       break;
  2878     case Op_ThreadLocal:
  2880       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
  2881       break;
  2883     default:
  2885       // nothing to do
  2887   return;
  2890 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
  2891   uint n_idx = n->_idx;
  2892   assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
  2894   // Don't set processed bit for AddP, LoadP, StoreP since
  2895   // they may need more then one pass to process.
  2896   // Also don't mark as processed Call nodes since their
  2897   // arguments may need more then one pass to process.
  2898   if (_processed.test(n_idx))
  2899     return; // No need to redefine node's state.
  2901   if (n->is_Call()) {
  2902     CallNode *call = n->as_Call();
  2903     process_call_arguments(call, phase);
  2904     return;
  2907   switch (n->Opcode()) {
  2908     case Op_AddP:
  2910       Node *base = get_addp_base(n);
  2911       int offset = address_offset(n, phase);
  2912       // Create a field edge to this node from everything base could point to.
  2913       for( VectorSetI i(PointsTo(base)); i.test(); ++i ) {
  2914         uint pt = i.elem;
  2915         add_field_edge(pt, n_idx, offset);
  2917       break;
  2919     case Op_CastX2P:
  2921       assert(false, "Op_CastX2P");
  2922       break;
  2924     case Op_CastPP:
  2925     case Op_CheckCastPP:
  2926     case Op_EncodeP:
  2927     case Op_DecodeN:
  2929       int ti = n->in(1)->_idx;
  2930       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
  2931       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  2932         add_pointsto_edge(n_idx, ti);
  2933       } else {
  2934         add_deferred_edge(n_idx, ti);
  2936       _processed.set(n_idx);
  2937       break;
  2939     case Op_ConP:
  2941       assert(false, "Op_ConP");
  2942       break;
  2944     case Op_ConN:
  2946       assert(false, "Op_ConN");
  2947       break;
  2949     case Op_CreateEx:
  2951       assert(false, "Op_CreateEx");
  2952       break;
  2954     case Op_LoadKlass:
  2955     case Op_LoadNKlass:
  2957       assert(false, "Op_LoadKlass");
  2958       break;
  2960     case Op_LoadP:
  2961     case Op_LoadN:
  2963       const Type *t = phase->type(n);
  2964 #ifdef ASSERT
  2965       if (t->make_ptr() == NULL)
  2966         assert(false, "Op_LoadP");
  2967 #endif
  2969       Node* adr = n->in(MemNode::Address)->uncast();
  2970       Node* adr_base;
  2971       if (adr->is_AddP()) {
  2972         adr_base = get_addp_base(adr);
  2973       } else {
  2974         adr_base = adr;
  2977       // For everything "adr_base" could point to, create a deferred edge from
  2978       // this node to each field with the same offset.
  2979       int offset = address_offset(adr, phase);
  2980       for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
  2981         uint pt = i.elem;
  2982         if (adr->is_AddP()) {
  2983           // Add field edge if it is missing.
  2984           add_field_edge(pt, adr->_idx, offset);
  2986         add_deferred_edge_to_fields(n_idx, pt, offset);
  2988       break;
  2990     case Op_Parm:
  2992       assert(false, "Op_Parm");
  2993       break;
  2995     case Op_PartialSubtypeCheck:
  2997       assert(false, "Op_PartialSubtypeCheck");
  2998       break;
  3000     case Op_Phi:
  3002 #ifdef ASSERT
  3003       const Type *t = n->as_Phi()->type();
  3004       if (t->make_ptr() == NULL)
  3005         assert(false, "Op_Phi");
  3006 #endif
  3007       for (uint i = 1; i < n->req() ; i++) {
  3008         Node* in = n->in(i);
  3009         if (in == NULL)
  3010           continue;  // ignore NULL
  3011         in = in->uncast();
  3012         if (in->is_top() || in == n)
  3013           continue;  // ignore top or inputs which go back this node
  3014         int ti = in->_idx;
  3015         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  3016         assert(nt != PointsToNode::UnknownType, "all nodes should be known");
  3017         if (nt == PointsToNode::JavaObject) {
  3018           add_pointsto_edge(n_idx, ti);
  3019         } else {
  3020           add_deferred_edge(n_idx, ti);
  3023       _processed.set(n_idx);
  3024       break;
  3026     case Op_Proj:
  3028       // we are only interested in the oop result projection from a call
  3029       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  3030         assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
  3031                "all nodes should be registered");
  3032         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  3033         assert(r->cnt() > TypeFunc::Parms, "sanity");
  3034         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  3035           process_call_result(n->as_Proj(), phase);
  3036           assert(_processed.test(n_idx), "all call results should be processed");
  3037           break;
  3040       assert(false, "Op_Proj");
  3041       break;
  3043     case Op_Return:
  3045 #ifdef ASSERT
  3046       if( n->req() <= TypeFunc::Parms ||
  3047           !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  3048         assert(false, "Op_Return");
  3050 #endif
  3051       int ti = n->in(TypeFunc::Parms)->_idx;
  3052       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
  3053       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  3054         add_pointsto_edge(n_idx, ti);
  3055       } else {
  3056         add_deferred_edge(n_idx, ti);
  3058       _processed.set(n_idx);
  3059       break;
  3061     case Op_StoreP:
  3062     case Op_StoreN:
  3063     case Op_StorePConditional:
  3064     case Op_CompareAndSwapP:
  3065     case Op_CompareAndSwapN:
  3067       Node *adr = n->in(MemNode::Address);
  3068       const Type *adr_type = phase->type(adr)->make_ptr();
  3069 #ifdef ASSERT
  3070       if (!adr_type->isa_oopptr())
  3071         assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
  3072 #endif
  3074       assert(adr->is_AddP(), "expecting an AddP");
  3075       Node *adr_base = get_addp_base(adr);
  3076       Node *val = n->in(MemNode::ValueIn)->uncast();
  3077       int offset = address_offset(adr, phase);
  3078       // For everything "adr_base" could point to, create a deferred edge
  3079       // to "val" from each field with the same offset.
  3080       for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
  3081         uint pt = i.elem;
  3082         // Add field edge if it is missing.
  3083         add_field_edge(pt, adr->_idx, offset);
  3084         add_edge_from_fields(pt, val->_idx, offset);
  3086       break;
  3088     case Op_AryEq:
  3089     case Op_StrComp:
  3090     case Op_StrEquals:
  3091     case Op_StrIndexOf:
  3093       // char[] arrays passed to string intrinsic do not escape but
  3094       // they are not scalar replaceable. Adjust escape state for them.
  3095       // Start from in(2) edge since in(1) is memory edge.
  3096       for (uint i = 2; i < n->req(); i++) {
  3097         Node* adr = n->in(i)->uncast();
  3098         const Type *at = phase->type(adr);
  3099         if (!adr->is_top() && at->isa_ptr()) {
  3100           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
  3101                  at->isa_ptr() != NULL, "expecting an Ptr");
  3102           if (adr->is_AddP()) {
  3103             adr = get_addp_base(adr);
  3105           // Mark as ArgEscape everything "adr" could point to.
  3106           set_escape_state(adr->_idx, PointsToNode::ArgEscape);
  3109       _processed.set(n_idx);
  3110       break;
  3112     case Op_ThreadLocal:
  3114       assert(false, "Op_ThreadLocal");
  3115       break;
  3117     default:
  3118       // This method should be called only for EA specific nodes.
  3119       ShouldNotReachHere();
  3123 #ifndef PRODUCT
  3124 void ConnectionGraph::dump() {
  3125   bool first = true;
  3127   uint size = nodes_size();
  3128   for (uint ni = 0; ni < size; ni++) {
  3129     PointsToNode *ptn = ptnode_adr(ni);
  3130     PointsToNode::NodeType ptn_type = ptn->node_type();
  3132     if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
  3133       continue;
  3134     PointsToNode::EscapeState es = escape_state(ptn->_node);
  3135     if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
  3136       if (first) {
  3137         tty->cr();
  3138         tty->print("======== Connection graph for ");
  3139         _compile->method()->print_short_name();
  3140         tty->cr();
  3141         first = false;
  3143       tty->print("%6d ", ni);
  3144       ptn->dump();
  3145       // Print all locals which reference this allocation
  3146       for (uint li = ni; li < size; li++) {
  3147         PointsToNode *ptn_loc = ptnode_adr(li);
  3148         PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
  3149         if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
  3150              ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
  3151           ptnode_adr(li)->dump(false);
  3154       if (Verbose) {
  3155         // Print all fields which reference this allocation
  3156         for (uint i = 0; i < ptn->edge_count(); i++) {
  3157           uint ei = ptn->edge_target(i);
  3158           ptnode_adr(ei)->dump(false);
  3161       tty->cr();
  3165 #endif

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