jdk8-mips64-public/hotspot: comparison src/share/vm/opto/escape.hpp

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+:f90c822e73f8
+/*
+* 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 / file comparison

comparison: src/share/vm/opto/escape.hpp

src/share/vm/opto/escape.hpp