jdk8-mips64-public/hotspot: src/share/vm/opto/escape.hpp@8c57262447d3 (annotated)

src/share/vm/opto/escape.hpp@8c57262447d3 (annotated)

src/share/vm/opto/escape.hpp

Mon, 14 Nov 2011 18:38:03 -0800

author: kvn
date: Mon, 14 Nov 2011 18:38:03 -0800
changeset 3309: 8c57262447d3
parent 3254: 59e515ee9354
child 3318: cc81b9c09bbb
permissions: -rw-r--r--

7105605: Use EA info to optimize pointers compare
Summary: optimize pointers compare using EA information.
Reviewed-by: never, twisti

 /*
  * Copyright (c) 2005, 2011, 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  Type;
 class  TypePtr;
 class  VectorSet;
 class PointsToNode {
 friend class ConnectionGraph;
 public:
   typedef enum {
     UnknownType = 0,
     JavaObject  = 1,
     LocalVar    = 2,
     Field       = 3
   } 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 {
     UnknownEdge   = 0,
     PointsToEdge  = 1,
     DeferredEdge  = 2,
     FieldEdge     = 3
   } EdgeType;
 private:
   enum {
     EdgeMask = 3,
     EdgeShift = 2,
     INITIAL_EDGE_COUNT = 4
   };
   NodeType             _type;
   EscapeState          _escape;
   GrowableArray<uint>* _edges; // outgoing edges
   Node* _node;                 // Ideal node corresponding to this PointsTo node.
   int   _offset;               // Object fields offsets.
   bool  _scalar_replaceable;   // Not escaped object could be replaced with scalar
 public:
   PointsToNode():
     _type(UnknownType),
     _escape(UnknownEscape),
     _edges(NULL),
     _node(NULL),
     _offset(-1),
     _scalar_replaceable(true) {}
   EscapeState escape_state() const { return _escape; }
   NodeType node_type() const { return _type;}
   int offset() { return _offset;}
   bool scalar_replaceable() { return _scalar_replaceable;}
   void set_offset(int offs) { _offset = offs;}
   void set_escape_state(EscapeState state) { _escape = state; }
   void set_node_type(NodeType ntype) {
     assert(_type == UnknownType || _type == ntype, "Can't change node type");
     _type = ntype;
   }
   void set_scalar_replaceable(bool v) { _scalar_replaceable = v; }
   // count of outgoing edges
   uint edge_count() const { return (_edges == NULL) ? 0 : _edges->length(); }
   // node index of target of outgoing edge "e"
   uint edge_target(uint e) const {
     assert(_edges != NULL, "valid edge index");
     return (_edges->at(e) >> EdgeShift);
   }
   // type of outgoing edge "e"
   EdgeType edge_type(uint e) const {
     assert(_edges != NULL, "valid edge index");
     return (EdgeType) (_edges->at(e) & EdgeMask);
   }
   // add a edge of the specified type pointing to the specified target
   void add_edge(uint targIdx, EdgeType et);
   // remove an edge of the specified type pointing to the specified target
   void remove_edge(uint targIdx, EdgeType et);
 #ifndef PRODUCT
   void dump(bool print_state=true) const;
 #endif
 };
 class ConnectionGraph: public ResourceObj {
 private:
   GrowableArray<PointsToNode>  _nodes; // Connection graph nodes indexed
                                        // by ideal node index.
   Unique_Node_List  _delayed_worklist; // Nodes to be processed before
                                        // the call build_connection_graph().
   GrowableArray<MergeMemNode *>  _mergemem_worklist; // List of all MergeMem nodes
   VectorSet                _processed; // Records which nodes have been
                                        // processed.
   bool                    _collecting; // Indicates whether escape information
                                        // is still being collected. If false,
                                        // no new nodes will be processed.
   bool                    _progress;   // Indicates whether new Graph's edges
                                        // were created.
   uint                _phantom_object; // Index of globally escaping object
                                        // that pointer values loaded from
                                        // a field which has not been set
                                        // are assumed to point to.
   uint                      _oop_null; // ConP(#NULL)->_idx
   uint                     _noop_null; // ConN(#NULL)->_idx
   Node*                     _pcmp_neq; // ConI(#CC_GT)
   Node*                      _pcmp_eq; // ConI(#CC_EQ)
   Compile *                  _compile; // Compile object for current compilation
   PhaseIterGVN *                _igvn; // Value numbering
   // Address of an element in _nodes.  Used when the element is to be modified
   PointsToNode *ptnode_adr(uint idx) const {
     // There should be no new ideal nodes during ConnectionGraph build,
     // growableArray::adr_at() will throw assert otherwise.
     return _nodes.adr_at(idx);
   }
   uint nodes_size() const { return _nodes.length(); }
   // Add node to ConnectionGraph.
   void add_node(Node *n, PointsToNode::NodeType nt, PointsToNode::EscapeState es, bool done);
   // offset of a field reference
   int address_offset(Node* adr, PhaseTransform *phase);
   // compute the escape state for arguments to a call
   void process_call_arguments(CallNode *call, PhaseTransform *phase);
   // compute the escape state for the return value of a call
   void process_call_result(ProjNode *resproj, PhaseTransform *phase);
   // Populate Connection Graph with Ideal nodes.
   void record_for_escape_analysis(Node *n, PhaseTransform *phase);
   // Build Connection Graph and set nodes escape state.
   void build_connection_graph(Node *n, PhaseTransform *phase);
   // walk the connection graph starting at the node corresponding to "n" and
   // add the index of everything it could point to, to "ptset".  This may cause
   // Phi's encountered to get (re)processed  (which requires "phase".)
   VectorSet* PointsTo(Node * n);
   // Reused structures for PointsTo().
   VectorSet            pt_ptset;
   VectorSet            pt_visited;
   GrowableArray<uint>  pt_worklist;
   //  Edge manipulation.  The "from_i" and "to_i" arguments are the
   //  node indices of the source and destination of the edge
   void add_pointsto_edge(uint from_i, uint to_i);
   void add_deferred_edge(uint from_i, uint to_i);
   void add_field_edge(uint from_i, uint to_i, int offs);
   // Add an edge of the specified type pointing to the specified target.
   // Set _progress if new edge is added.
   void add_edge(PointsToNode *f, uint to_i, PointsToNode::EdgeType et) {
     uint e_cnt = f->edge_count();
     f->add_edge(to_i, et);
     _progress |= (f->edge_count() != e_cnt);
   }
   // Add an edge to node given by "to_i" from any field of adr_i whose offset
   // matches "offset"  A deferred edge is added if to_i is a LocalVar, and
   // a pointsto edge is added if it is a JavaObject
   void add_edge_from_fields(uint adr, uint to_i, int offs);
   // Add a deferred  edge from node given by "from_i" to any field
   // of adr_i whose offset matches "offset"
   void add_deferred_edge_to_fields(uint from_i, uint adr, int offs);
   // Remove outgoing deferred edges from the node referenced by "ni".
   // Any outgoing edges from the target of the deferred edge are copied
   // to "ni".
   void remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited);
   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
   bool split_AddP(Node *addp, Node *base,  PhaseGVN  *igvn);
   PhiNode *create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created);
   PhiNode *split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn);
   void  move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn);
   Node *find_inst_mem(Node *mem, int alias_idx,GrowableArray<PhiNode *>  &orig_phi_worklist,  PhaseGVN  *igvn);
   // Propagate unique types created for unescaped allocated objects
   // through the graph
   void split_unique_types(GrowableArray<Node *>  &alloc_worklist);
   // manage entries in _node_map
   void  set_map(int idx, Node *n)        { _node_map.map(idx, n); }
   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
   // Node:  This assumes that escape analysis is run before
   //        PhaseIterGVN creation
   void record_for_optimizer(Node *n) {
     _igvn->_worklist.push(n);
   }
   // Set the escape state of a node
   void set_escape_state(uint ni, PointsToNode::EscapeState es);
   // Find fields initializing values for allocations.
   void find_init_values(Node* n, VectorSet* visited, PhaseTransform* phase);
   // Adjust escape state after Connection Graph is built.
   void adjust_escape_state(Node* n);
   // Propagate escape states to referenced nodes.
   bool propagate_escape_state(GrowableArray<int>* cg_worklist,
                               GrowableArray<uint>* worklist,
                               PointsToNode::EscapeState esc_state);
   // Optimize objects compare.
   Node* optimize_ptr_compare(Node* 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);
   // escape state of a node
   PointsToNode::EscapeState escape_state(Node *n);
 #ifndef PRODUCT
   void dump();
 #endif
 };
 #endif // SHARE_VM_OPTO_ESCAPE_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/escape.hpp@8c57262447d3 (annotated)

src/share/vm/opto/escape.hpp