jdk8-mips64-public/hotspot: src/share/vm/opto/escape.hpp@f90c822e73f8 (annotated)

src/share/vm/opto/escape.hpp@f90c822e73f8 (annotated)

src/share/vm/opto/escape.hpp

Wed, 27 Apr 2016 01:25:04 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:25:04 +0800
changeset 0: f90c822e73f8
child 6876: 710a3c8b516e
permissions: -rw-r--r--

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changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

 /*
  * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_OPTO_ESCAPE_HPP
 #define SHARE_VM_OPTO_ESCAPE_HPP
 #include "opto/addnode.hpp"
 #include "opto/node.hpp"
 #include "utilities/growableArray.hpp"
 //
 // Adaptation for C2 of the escape analysis algorithm described in:
 //
 // [Choi99] Jong-Deok Shoi, Manish Gupta, Mauricio Seffano,
 //          Vugranam C. Sreedhar, Sam Midkiff,
 //          "Escape Analysis for Java", Procedings of ACM SIGPLAN
 //          OOPSLA  Conference, November 1, 1999
 //
 // The flow-insensitive analysis described in the paper has been implemented.
 //
 // The analysis requires construction of a "connection graph" (CG) for
 // the method being analyzed.  The nodes of the connection graph are:
 //
 //     -  Java objects (JO)
 //     -  Local variables (LV)
 //     -  Fields of an object (OF),  these also include array elements
 //
 // The CG contains 3 types of edges:
 //
 //   -  PointsTo  (-P>)    {LV, OF} to JO
 //   -  Deferred  (-D>)    from {LV, OF} to {LV, OF}
 //   -  Field     (-F>)    from JO to OF
 //
 // The following  utility functions is used by the algorithm:
 //
 //   PointsTo(n) - n is any CG node, it returns the set of JO that n could
 //                 point to.
 //
 // The algorithm describes how to construct the connection graph
 // in the following 4 cases:
 //
 //          Case                  Edges Created
 //
 // (1)   p   = new T()              LV -P> JO
 // (2)   p   = q                    LV -D> LV
 // (3)   p.f = q                    JO -F> OF,  OF -D> LV
 // (4)   p   = q.f                  JO -F> OF,  LV -D> OF
 //
 // In all these cases, p and q are local variables.  For static field
 // references, we can construct a local variable containing a reference
 // to the static memory.
 //
 // C2 does not have local variables.  However for the purposes of constructing
 // the connection graph, the following IR nodes are treated as local variables:
 //     Phi    (pointer values)
 //     LoadP, LoadN
 //     Proj#5 (value returned from callnodes including allocations)
 //     CheckCastPP, CastPP
 //
 // The LoadP, Proj and CheckCastPP behave like variables assigned to only once.
 // Only a Phi can have multiple assignments.  Each input to a Phi is treated
 // as an assignment to it.
 //
 // The following node types are JavaObject:
 //
 //     phantom_object (general globally escaped object)
 //     Allocate
 //     AllocateArray
 //     Parm  (for incoming arguments)
 //     CastX2P ("unsafe" operations)
 //     CreateEx
 //     ConP
 //     LoadKlass
 //     ThreadLocal
 //     CallStaticJava (which returns Object)
 //
 // AddP nodes are fields.
 //
 // After building the graph, a pass is made over the nodes, deleting deferred
 // nodes and copying the edges from the target of the deferred edge to the
 // source.  This results in a graph with no deferred edges, only:
 //
 //    LV -P> JO
 //    OF -P> JO (the object whose oop is stored in the field)
 //    JO -F> OF
 //
 // Then, for each node which is GlobalEscape, anything it could point to
 // is marked GlobalEscape.  Finally, for any node marked ArgEscape, anything
 // it could point to is marked ArgEscape.
 //
 class  Compile;
 class  Node;
 class  CallNode;
 class  PhiNode;
 class  PhaseTransform;
 class  PointsToNode;
 class  Type;
 class  TypePtr;
 class  VectorSet;
 class JavaObjectNode;
 class LocalVarNode;
 class FieldNode;
 class ArraycopyNode;
 // ConnectionGraph nodes
 class PointsToNode : public ResourceObj {
   GrowableArray<PointsToNode*> _edges; // List of nodes this node points to
   GrowableArray<PointsToNode*> _uses;  // List of nodes which point to this node
   const u1           _type;  // NodeType
   u1                _flags;  // NodeFlags
   u1               _escape;  // EscapeState of object
   u1        _fields_escape;  // EscapeState of object's fields
   Node* const        _node;  // Ideal node corresponding to this PointsTo node.
   const int           _idx;  // Cached ideal node's _idx
 public:
   typedef enum {
     UnknownType = 0,
     JavaObject  = 1,
     LocalVar    = 2,
     Field       = 3,
     Arraycopy   = 4
   } NodeType;
   typedef enum {
     UnknownEscape = 0,
     NoEscape      = 1, // An object does not escape method or thread and it is
                        // not passed to call. It could be replaced with scalar.
     ArgEscape     = 2, // An object does not escape method or thread but it is
                        // passed as argument to call or referenced by argument
                        // and it does not escape during call.
     GlobalEscape  = 3  // An object escapes the method or thread.
   } EscapeState;
   typedef enum {
     ScalarReplaceable = 1,  // Not escaped object could be replaced with scalar
     PointsToUnknown   = 2,  // Has edge to phantom_object
     ArraycopySrc      = 4,  // Has edge from Arraycopy node
     ArraycopyDst      = 8   // Has edge to Arraycopy node
   } NodeFlags;
   PointsToNode(Compile *C, Node* n, EscapeState es, NodeType type):
     _edges(C->comp_arena(), 2, 0, NULL),
     _uses (C->comp_arena(), 2, 0, NULL),
     _node(n),
     _idx(n->_idx),
     _type((u1)type),
     _escape((u1)es),
     _fields_escape((u1)es),
     _flags(ScalarReplaceable) {
     assert(n != NULL && es != UnknownEscape, "sanity");
   }
   Node* ideal_node()   const { return _node; }
   int          idx()   const { return _idx; }
   bool is_JavaObject() const { return _type == (u1)JavaObject; }
   bool is_LocalVar()   const { return _type == (u1)LocalVar; }
   bool is_Field()      const { return _type == (u1)Field; }
   bool is_Arraycopy()  const { return _type == (u1)Arraycopy; }
   JavaObjectNode* as_JavaObject() { assert(is_JavaObject(),""); return (JavaObjectNode*)this; }
   LocalVarNode*   as_LocalVar()   { assert(is_LocalVar(),"");   return (LocalVarNode*)this; }
   FieldNode*      as_Field()      { assert(is_Field(),"");      return (FieldNode*)this; }
   ArraycopyNode*  as_Arraycopy()  { assert(is_Arraycopy(),"");  return (ArraycopyNode*)this; }
   EscapeState escape_state() const { return (EscapeState)_escape; }
   void    set_escape_state(EscapeState state) { _escape = (u1)state; }
   EscapeState fields_escape_state() const { return (EscapeState)_fields_escape; }
   void    set_fields_escape_state(EscapeState state) { _fields_escape = (u1)state; }
   bool     has_unknown_ptr() const { return (_flags & PointsToUnknown) != 0; }
   void set_has_unknown_ptr()       { _flags |= PointsToUnknown; }
   bool     arraycopy_src() const { return (_flags & ArraycopySrc) != 0; }
   void set_arraycopy_src()       { _flags |= ArraycopySrc; }
   bool     arraycopy_dst() const { return (_flags & ArraycopyDst) != 0; }
   void set_arraycopy_dst()       { _flags |= ArraycopyDst; }
   bool     scalar_replaceable() const { return (_flags & ScalarReplaceable) != 0;}
   void set_scalar_replaceable(bool v) {
     if (v)
       _flags |= ScalarReplaceable;
     else
       _flags &= ~ScalarReplaceable;
   }
   int edge_count()              const { return _edges.length(); }
   PointsToNode* edge(int e)     const { return _edges.at(e); }
   bool add_edge(PointsToNode* edge)    { return _edges.append_if_missing(edge); }
   int use_count()             const { return _uses.length(); }
   PointsToNode* use(int e)    const { return _uses.at(e); }
   bool add_use(PointsToNode* use)    { return _uses.append_if_missing(use); }
   // Mark base edge use to distinguish from stored value edge.
   bool add_base_use(FieldNode* use) { return _uses.append_if_missing((PointsToNode*)((intptr_t)use + 1)); }
   static bool is_base_use(PointsToNode* use) { return (((intptr_t)use) & 1); }
   static PointsToNode* get_use_node(PointsToNode* use) { return (PointsToNode*)(((intptr_t)use) & ~1); }
   // Return true if this node points to specified node or nodes it points to.
   bool points_to(JavaObjectNode* ptn) const;
   // Return true if this node points only to non-escaping allocations.
   bool non_escaping_allocation();
   // Return true if one node points to an other.
   bool meet(PointsToNode* ptn);
 #ifndef PRODUCT
   NodeType node_type() const { return (NodeType)_type;}
   void dump(bool print_state=true) const;
 #endif
 };
 class LocalVarNode: public PointsToNode {
 public:
   LocalVarNode(Compile *C, Node* n, EscapeState es):
     PointsToNode(C, n, es, LocalVar) {}
 };
 class JavaObjectNode: public PointsToNode {
 public:
   JavaObjectNode(Compile *C, Node* n, EscapeState es):
     PointsToNode(C, n, es, JavaObject) {
       if (es > NoEscape)
         set_scalar_replaceable(false);
     }
 };
 class FieldNode: public PointsToNode {
   GrowableArray<PointsToNode*> _bases; // List of JavaObject nodes which point to this node
   const int   _offset; // Field's offset.
   const bool  _is_oop; // Field points to object
         bool  _has_unknown_base; // Has phantom_object base
 public:
   FieldNode(Compile *C, Node* n, EscapeState es, int offs, bool is_oop):
     PointsToNode(C, n, es, Field),
     _offset(offs), _is_oop(is_oop),
     _has_unknown_base(false) {}
   int      offset()              const { return _offset;}
   bool     is_oop()              const { return _is_oop;}
   bool     has_unknown_base()    const { return _has_unknown_base; }
   void set_has_unknown_base()          { _has_unknown_base = true; }
   int base_count()              const { return _bases.length(); }
   PointsToNode* base(int e)     const { return _bases.at(e); }
   bool add_base(PointsToNode* base)    { return _bases.append_if_missing(base); }
 #ifdef ASSERT
   // Return true if bases points to this java object.
   bool has_base(JavaObjectNode* ptn) const;
 #endif
 };
 class ArraycopyNode: public PointsToNode {
 public:
   ArraycopyNode(Compile *C, Node* n, EscapeState es):
     PointsToNode(C, n, es, Arraycopy) {}
 };
 // Iterators for PointsTo node's edges:
 //   for (EdgeIterator i(n); i.has_next(); i.next()) {
 //     PointsToNode* u = i.get();
 class PointsToIterator: public StackObj {
 protected:
   const PointsToNode* node;
   const int cnt;
   int i;
 public:
   inline PointsToIterator(const PointsToNode* n, int cnt) : node(n), cnt(cnt), i(0) { }
   inline bool has_next() const { return i < cnt; }
   inline void next() { i++; }
   PointsToNode* get() const { ShouldNotCallThis(); return NULL; }
 };
 class EdgeIterator: public PointsToIterator {
 public:
   inline EdgeIterator(const PointsToNode* n) : PointsToIterator(n, n->edge_count()) { }
   inline PointsToNode* get() const { return node->edge(i); }
 };
 class UseIterator: public PointsToIterator {
 public:
   inline UseIterator(const PointsToNode* n) : PointsToIterator(n, n->use_count()) { }
   inline PointsToNode* get() const { return node->use(i); }
 };
 class BaseIterator: public PointsToIterator {
 public:
   inline BaseIterator(const FieldNode* n) : PointsToIterator(n, n->base_count()) { }
   inline PointsToNode* get() const { return ((PointsToNode*)node)->as_Field()->base(i); }
 };
 class ConnectionGraph: public ResourceObj {
 private:
   GrowableArray<PointsToNode*>  _nodes; // Map from ideal nodes to
                                         // ConnectionGraph nodes.
   GrowableArray<PointsToNode*>  _worklist; // Nodes to be processed
   bool            _collecting; // Indicates whether escape information
                                // is still being collected. If false,
                                // no new nodes will be processed.
   bool               _verify;  // verify graph
   JavaObjectNode* phantom_obj; // Unknown object
   JavaObjectNode*    null_obj;
   Node*             _pcmp_neq; // ConI(#CC_GT)
   Node*              _pcmp_eq; // ConI(#CC_EQ)
   Compile*           _compile; // Compile object for current compilation
   PhaseIterGVN*         _igvn; // Value numbering
   Unique_Node_List ideal_nodes; // Used by CG construction and types splitting.
   // Address of an element in _nodes.  Used when the element is to be modified
   PointsToNode* ptnode_adr(int idx) const {
     // There should be no new ideal nodes during ConnectionGraph build,
     // growableArray::at() will throw assert otherwise.
     return _nodes.at(idx);
   }
   uint nodes_size() const { return _nodes.length(); }
   // Add nodes to ConnectionGraph.
   void add_local_var(Node* n, PointsToNode::EscapeState es);
   void add_java_object(Node* n, PointsToNode::EscapeState es);
   void add_field(Node* n, PointsToNode::EscapeState es, int offset);
   void add_arraycopy(Node* n, PointsToNode::EscapeState es, PointsToNode* src, PointsToNode* dst);
   // Compute the escape state for arguments to a call.
   void process_call_arguments(CallNode *call);
   // Add PointsToNode node corresponding to a call
   void add_call_node(CallNode* call);
   // Map ideal node to existing PointsTo node (usually phantom_object).
   void map_ideal_node(Node *n, PointsToNode* ptn) {
     assert(ptn != NULL, "only existing PointsTo node");
     _nodes.at_put(n->_idx, ptn);
   }
   // Utility function for nodes that load an object
   void add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist);
   // Create PointsToNode node and add it to Connection Graph.
   void add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist);
   // Add final simple edges to graph.
   void add_final_edges(Node *n);
   // Finish Graph construction.
   bool complete_connection_graph(GrowableArray<PointsToNode*>&   ptnodes_worklist,
                                  GrowableArray<JavaObjectNode*>& non_escaped_worklist,
                                  GrowableArray<JavaObjectNode*>& java_objects_worklist,
                                  GrowableArray<FieldNode*>&      oop_fields_worklist);
 #ifdef ASSERT
   void verify_connection_graph(GrowableArray<PointsToNode*>&   ptnodes_worklist,
                                GrowableArray<JavaObjectNode*>& non_escaped_worklist,
                                GrowableArray<JavaObjectNode*>& java_objects_worklist,
                                GrowableArray<Node*>& addp_worklist);
 #endif
   // Add all references to this JavaObject node.
   int add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist);
   // Put node on worklist if it is (or was) not there.
   void add_to_worklist(PointsToNode* pt) {
     _worklist.push(pt);
     return;
   }
   // Put on worklist all uses of this node.
   void add_uses_to_worklist(PointsToNode* pt) {
     for (UseIterator i(pt); i.has_next(); i.next())
       _worklist.push(i.get());
   }
   // Put on worklist all field's uses and related field nodes.
   void add_field_uses_to_worklist(FieldNode* field);
   // Put on worklist all related field nodes.
   void add_fields_to_worklist(FieldNode* field, PointsToNode* base);
   // Find fields which have unknown value.
   int find_field_value(FieldNode* field);
   // Find fields initializing values for allocations.
   int find_init_values(JavaObjectNode* ptn, PointsToNode* init_val, PhaseTransform* phase);
   // Set the escape state of an object and its fields.
   void set_escape_state(PointsToNode* ptn, PointsToNode::EscapeState esc) {
     // Don't change non-escaping state of NULL pointer.
     if (ptn != null_obj) {
       if (ptn->escape_state() < esc)
         ptn->set_escape_state(esc);
       if (ptn->fields_escape_state() < esc)
         ptn->set_fields_escape_state(esc);
     }
   }
   void set_fields_escape_state(PointsToNode* ptn, PointsToNode::EscapeState esc) {
     // Don't change non-escaping state of NULL pointer.
     if (ptn != null_obj) {
       if (ptn->fields_escape_state() < esc)
         ptn->set_fields_escape_state(esc);
     }
   }
   // Propagate GlobalEscape and ArgEscape escape states to all nodes
   // and check that we still have non-escaping java objects.
   bool find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
                                 GrowableArray<JavaObjectNode*>& non_escaped_worklist);
   // Adjust scalar_replaceable state after Connection Graph is built.
   void adjust_scalar_replaceable_state(JavaObjectNode* jobj);
   // Optimize ideal graph.
   void optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
                             GrowableArray<Node*>& storestore_worklist);
   // Optimize objects compare.
   Node* optimize_ptr_compare(Node* n);
   // Returns unique corresponding java object or NULL.
   JavaObjectNode* unique_java_object(Node *n);
   // Add an edge of the specified type pointing to the specified target.
   bool add_edge(PointsToNode* from, PointsToNode* to) {
     assert(!from->is_Field() || from->as_Field()->is_oop(), "sanity");
     if (to == phantom_obj) {
       if (from->has_unknown_ptr()) {
         return false; // already points to phantom_obj
       }
       from->set_has_unknown_ptr();
     }
     bool is_new = from->add_edge(to);
     assert(to != phantom_obj || is_new, "sanity");
     if (is_new) { // New edge?
       assert(!_verify, "graph is incomplete");
       is_new = to->add_use(from);
       assert(is_new, "use should be also new");
     }
     return is_new;
   }
   // Add an edge from Field node to its base and back.
   bool add_base(FieldNode* from, PointsToNode* to) {
     assert(!to->is_Arraycopy(), "sanity");
     if (to == phantom_obj) {
       if (from->has_unknown_base()) {
         return false; // already has phantom_obj base
       }
       from->set_has_unknown_base();
     }
     bool is_new = from->add_base(to);
     assert(to != phantom_obj || is_new, "sanity");
     if (is_new) {      // New edge?
       assert(!_verify, "graph is incomplete");
       if (to == null_obj)
         return is_new; // Don't add fields to NULL pointer.
       if (to->is_JavaObject()) {
         is_new = to->add_edge(from);
       } else {
         is_new = to->add_base_use(from);
       }
       assert(is_new, "use should be also new");
     }
     return is_new;
   }
   // Add LocalVar node and edge if possible
   void add_local_var_and_edge(Node* n, PointsToNode::EscapeState es, Node* to,
                               Unique_Node_List *delayed_worklist) {
     PointsToNode* ptn = ptnode_adr(to->_idx);
     if (delayed_worklist != NULL) { // First iteration of CG construction
       add_local_var(n, es);
       if (ptn == NULL) {
         delayed_worklist->push(n);
         return; // Process it later.
       }
     } else {
       assert(ptn != NULL, "node should be registered");
     }
     add_edge(ptnode_adr(n->_idx), ptn);
  }
   // Helper functions
   bool   is_oop_field(Node* n, int offset, bool* unsafe);
  static Node* get_addp_base(Node *addp);
  static Node* find_second_addp(Node* addp, Node* n);
   // offset of a field reference
   int address_offset(Node* adr, PhaseTransform *phase);
   // Propagate unique types created for unescaped allocated objects
   // through the graph
   void split_unique_types(GrowableArray<Node *>  &alloc_worklist);
   // Helper methods for unique types split.
   bool split_AddP(Node *addp, Node *base);
   PhiNode *create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created);
   PhiNode *split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist);
   void  move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis);
   Node* find_inst_mem(Node* mem, int alias_idx,GrowableArray<PhiNode *>  &orig_phi_worklist);
   Node* step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop);
   GrowableArray<MergeMemNode*>  _mergemem_worklist; // List of all MergeMem nodes
   Node_Array _node_map; // used for bookeeping during type splitting
                         // Used for the following purposes:
                         // Memory Phi    - most recent unique Phi split out
                         //                 from this Phi
                         // MemNode       - new memory input for this node
                         // ChecCastPP    - allocation that this is a cast of
                         // allocation    - CheckCastPP of the allocation
   // manage entries in _node_map
   void  set_map(Node* from, Node* to)  {
     ideal_nodes.push(from);
     _node_map.map(from->_idx, to);
   }
   Node* get_map(int idx) { return _node_map[idx]; }
   PhiNode* get_map_phi(int idx) {
     Node* phi = _node_map[idx];
     return (phi == NULL) ? NULL : phi->as_Phi();
   }
   // Notify optimizer that a node has been modified
   void record_for_optimizer(Node *n) {
     _igvn->_worklist.push(n);
     _igvn->add_users_to_worklist(n);
   }
   // Compute the escape information
   bool compute_escape();
 public:
   ConnectionGraph(Compile *C, PhaseIterGVN *igvn);
   // Check for non-escaping candidates
   static bool has_candidates(Compile *C);
   // Perform escape analysis
   static void do_analysis(Compile *C, PhaseIterGVN *igvn);
   bool not_global_escape(Node *n);
 #ifndef PRODUCT
   void dump(GrowableArray<PointsToNode*>& ptnodes_worklist);
 #endif
 };
 #endif // SHARE_VM_OPTO_ESCAPE_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/escape.hpp@f90c822e73f8 (annotated)

src/share/vm/opto/escape.hpp