jdk8-mips64-public/hotspot: src/share/vm/opto/phaseX.hpp@1bd45abaa507 (annotated)

src/share/vm/opto/phaseX.hpp@1bd45abaa507 (annotated)

src/share/vm/opto/phaseX.hpp

Wed, 16 Nov 2011 09:13:57 -0800

author: kvn
date: Wed, 16 Nov 2011 09:13:57 -0800
changeset 3311: 1bd45abaa507
parent 3043: c96c3eb1efae
child 3407: 35acf8f0a2e4
permissions: -rw-r--r--

6890673: Eliminate allocations immediately after EA
Summary: Try to eliminate allocations and related locks immediately after escape analysis.
Reviewed-by: never

 /*
  * Copyright (c) 1997, 2010, 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_PHASEX_HPP
 #define SHARE_VM_OPTO_PHASEX_HPP
 #include "libadt/dict.hpp"
 #include "libadt/vectset.hpp"
 #include "memory/resourceArea.hpp"
 #include "opto/memnode.hpp"
 #include "opto/node.hpp"
 #include "opto/phase.hpp"
 #include "opto/type.hpp"
 class Compile;
 class ConINode;
 class ConLNode;
 class Node;
 class Type;
 class PhaseTransform;
 class   PhaseGVN;
 class     PhaseIterGVN;
 class       PhaseCCP;
 class   PhasePeephole;
 class   PhaseRegAlloc;
 //-----------------------------------------------------------------------------
 // Expandable closed hash-table of nodes, initialized to NULL.
 // Note that the constructor just zeros things
 // Storage is reclaimed when the Arena's lifetime is over.
 class NodeHash : public StackObj {
 protected:
   Arena *_a;                    // Arena to allocate in
   uint   _max;                  // Size of table (power of 2)
   uint   _inserts;              // For grow and debug, count of hash_inserts
   uint   _insert_limit;         // 'grow' when _inserts reaches _insert_limit
   Node **_table;                // Hash table of Node pointers
   Node  *_sentinel;             // Replaces deleted entries in hash table
 public:
   NodeHash(uint est_max_size);
   NodeHash(Arena *arena, uint est_max_size);
   NodeHash(NodeHash *use_this_state);
 #ifdef ASSERT
   ~NodeHash();                  // Unlock all nodes upon destruction of table.
   void operator=(const NodeHash&); // Unlock all nodes upon replacement of table.
 #endif
   Node  *hash_find(const Node*);// Find an equivalent version in hash table
   Node  *hash_find_insert(Node*);// If not in table insert else return found node
   void   hash_insert(Node*);    // Insert into hash table
   bool   hash_delete(const Node*);// Replace with _sentinel in hash table
   void   check_grow() {
     _inserts++;
     if( _inserts == _insert_limit ) { grow(); }
     assert( _inserts <= _insert_limit, "hash table overflow");
     assert( _inserts < _max, "hash table overflow" );
   }
   static uint round_up(uint);   // Round up to nearest power of 2
   void   grow();                // Grow _table to next power of 2 and rehash
   // Return 75% of _max, rounded up.
   uint   insert_limit() const { return _max - (_max>>2); }
   void   clear();               // Set all entries to NULL, keep storage.
   // Size of hash table
   uint   size()         const { return _max; }
   // Return Node* at index in table
   Node  *at(uint table_index) {
     assert(table_index < _max, "Must be within table");
     return _table[table_index];
   }
   void   remove_useless_nodes(VectorSet &useful); // replace with sentinel
   Node  *sentinel() { return _sentinel; }
 #ifndef PRODUCT
   Node  *find_index(uint idx);  // For debugging
   void   dump();                // For debugging, dump statistics
 #endif
   uint   _grows;                // For debugging, count of table grow()s
   uint   _look_probes;          // For debugging, count of hash probes
   uint   _lookup_hits;          // For debugging, count of hash_finds
   uint   _lookup_misses;        // For debugging, count of hash_finds
   uint   _insert_probes;        // For debugging, count of hash probes
   uint   _delete_probes;        // For debugging, count of hash probes for deletes
   uint   _delete_hits;          // For debugging, count of hash probes for deletes
   uint   _delete_misses;        // For debugging, count of hash probes for deletes
   uint   _total_inserts;        // For debugging, total inserts into hash table
   uint   _total_insert_probes;  // For debugging, total probes while inserting
 };
 //-----------------------------------------------------------------------------
 // Map dense integer indices to Types.  Uses classic doubling-array trick.
 // Abstractly provides an infinite array of Type*'s, initialized to NULL.
 // Note that the constructor just zeros things, and since I use Arena
 // allocation I do not need a destructor to reclaim storage.
 // Despite the general name, this class is customized for use by PhaseTransform.
 class Type_Array : public StackObj {
   Arena *_a;                    // Arena to allocate in
   uint   _max;
   const Type **_types;
   void grow( uint i );          // Grow array node to fit
   const Type *operator[] ( uint i ) const // Lookup, or NULL for not mapped
   { return (i<_max) ? _types[i] : (Type*)NULL; }
   friend class PhaseTransform;
 public:
   Type_Array(Arena *a) : _a(a), _max(0), _types(0) {}
   Type_Array(Type_Array *ta) : _a(ta->_a), _max(ta->_max), _types(ta->_types) { }
   const Type *fast_lookup(uint i) const{assert(i<_max,"oob");return _types[i];}
   // Extend the mapping: index i maps to Type *n.
   void map( uint i, const Type *n ) { if( i>=_max ) grow(i); _types[i] = n; }
   uint Size() const { return _max; }
 #ifndef PRODUCT
   void dump() const;
 #endif
 };
 //------------------------------PhaseRemoveUseless-----------------------------
 // Remove useless nodes from GVN hash-table, worklist, and graph
 class PhaseRemoveUseless : public Phase {
 protected:
   Unique_Node_List _useful;   // Nodes reachable from root
                               // list is allocated from current resource area
 public:
   PhaseRemoveUseless( PhaseGVN *gvn, Unique_Node_List *worklist );
   Unique_Node_List *get_useful() { return &_useful; }
 };
 //------------------------------PhaseTransform---------------------------------
 // Phases that analyze, then transform.  Constructing the Phase object does any
 // global or slow analysis.  The results are cached later for a fast
 // transformation pass.  When the Phase object is deleted the cached analysis
 // results are deleted.
 class PhaseTransform : public Phase {
 protected:
   Arena*     _arena;
   Node_Array _nodes;           // Map old node indices to new nodes.
   Type_Array _types;           // Map old node indices to Types.
   // ConNode caches:
   enum { _icon_min = -1 * HeapWordSize,
          _icon_max = 16 * HeapWordSize,
          _lcon_min = _icon_min,
          _lcon_max = _icon_max,
          _zcon_max = (uint)T_CONFLICT
   };
   ConINode* _icons[_icon_max - _icon_min + 1];   // cached jint constant nodes
   ConLNode* _lcons[_lcon_max - _lcon_min + 1];   // cached jlong constant nodes
   ConNode*  _zcons[_zcon_max + 1];               // cached is_zero_type nodes
   void init_con_caches();
   // Support both int and long caches because either might be an intptr_t,
   // so they show up frequently in address computations.
 public:
   PhaseTransform( PhaseNumber pnum );
   PhaseTransform( Arena *arena, PhaseNumber pnum );
   PhaseTransform( PhaseTransform *phase, PhaseNumber pnum );
   Arena*      arena()   { return _arena; }
   Type_Array& types()   { return _types; }
   // _nodes is used in varying ways by subclasses, which define local accessors
 public:
   // Get a previously recorded type for the node n.
   // This type must already have been recorded.
   // If you want the type of a very new (untransformed) node,
   // you must use type_or_null, and test the result for NULL.
   const Type* type(const Node* n) const {
     const Type* t = _types.fast_lookup(n->_idx);
     assert(t != NULL, "must set before get");
     return t;
   }
   // Get a previously recorded type for the node n,
   // or else return NULL if there is none.
   const Type* type_or_null(const Node* n) const {
     return _types.fast_lookup(n->_idx);
   }
   // Record a type for a node.
   void    set_type(const Node* n, const Type *t) {
     assert(t != NULL, "type must not be null");
     _types.map(n->_idx, t);
   }
   // Record an initial type for a node, the node's bottom type.
   void    set_type_bottom(const Node* n) {
     // Use this for initialization when bottom_type() (or better) is not handy.
     // Usually the initialization shoudl be to n->Value(this) instead,
     // or a hand-optimized value like Type::MEMORY or Type::CONTROL.
     assert(_types[n->_idx] == NULL, "must set the initial type just once");
     _types.map(n->_idx, n->bottom_type());
   }
   // Make sure the types array is big enough to record a size for the node n.
   // (In product builds, we never want to do range checks on the types array!)
   void ensure_type_or_null(const Node* n) {
     if (n->_idx >= _types.Size())
       _types.map(n->_idx, NULL);   // Grow the types array as needed.
   }
   // Utility functions:
   const TypeInt*  find_int_type( Node* n);
   const TypeLong* find_long_type(Node* n);
   jint  find_int_con( Node* n, jint  value_if_unknown) {
     const TypeInt* t = find_int_type(n);
     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
   }
   jlong find_long_con(Node* n, jlong value_if_unknown) {
     const TypeLong* t = find_long_type(n);
     return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
   }
   // Make an idealized constant, i.e., one of ConINode, ConPNode, ConFNode, etc.
   // Same as transform(ConNode::make(t)).
   ConNode* makecon(const Type* t);
   virtual ConNode* uncached_makecon(const Type* t)  // override in PhaseValues
   { ShouldNotCallThis(); return NULL; }
   // Fast int or long constant.  Same as TypeInt::make(i) or TypeLong::make(l).
   ConINode* intcon(jint i);
   ConLNode* longcon(jlong l);
   // Fast zero or null constant.  Same as makecon(Type::get_zero_type(bt)).
   ConNode* zerocon(BasicType bt);
   // Return a node which computes the same function as this node, but
   // in a faster or cheaper fashion.
   virtual Node *transform( Node *n ) = 0;
   // Return whether two Nodes are equivalent.
   // Must not be recursive, since the recursive version is built from this.
   // For pessimistic optimizations this is simply pointer equivalence.
   bool eqv(const Node* n1, const Node* n2) const { return n1 == n2; }
   // Return whether two Nodes are equivalent, after stripping casting.
   bool eqv_uncast(const Node* n1, const Node* n2) const {
     return eqv(n1->uncast(), n2->uncast());
   }
   // For pessimistic passes, the return type must monotonically narrow.
   // For optimistic  passes, the return type must monotonically widen.
   // It is possible to get into a "death march" in either type of pass,
   // where the types are continually moving but it will take 2**31 or
   // more steps to converge.  This doesn't happen on most normal loops.
   //
   // Here is an example of a deadly loop for an optimistic pass, along
   // with a partial trace of inferred types:
   //    x = phi(0,x'); L: x' = x+1; if (x' >= 0) goto L;
   //    0                 1                join([0..max], 1)
   //    [0..1]            [1..2]           join([0..max], [1..2])
   //    [0..2]            [1..3]           join([0..max], [1..3])
   //      ... ... ...
   //    [0..max]          [min]u[1..max]   join([0..max], [min..max])
   //    [0..max] ==> fixpoint
   // We would have proven, the hard way, that the iteration space is all
   // non-negative ints, with the loop terminating due to 32-bit overflow.
   //
   // Here is the corresponding example for a pessimistic pass:
   //    x = phi(0,x'); L: x' = x-1; if (x' >= 0) goto L;
   //    int               int              join([0..max], int)
   //    [0..max]          [-1..max-1]      join([0..max], [-1..max-1])
   //    [0..max-1]        [-1..max-2]      join([0..max], [-1..max-2])
   //      ... ... ...
   //    [0..1]            [-1..0]          join([0..max], [-1..0])
   //    0                 -1               join([0..max], -1)
   //    0 == fixpoint
   // We would have proven, the hard way, that the iteration space is {0}.
   // (Usually, other optimizations will make the "if (x >= 0)" fold up
   // before we get into trouble.  But not always.)
   //
   // It's a pleasant thing to observe that the pessimistic pass
   // will make short work of the optimistic pass's deadly loop,
   // and vice versa.  That is a good example of the complementary
   // purposes of the CCP (optimistic) vs. GVN (pessimistic) phases.
   //
   // In any case, only widen or narrow a few times before going to the
   // correct flavor of top or bottom.
   //
   // This call only needs to be made once as the data flows around any
   // given cycle.  We do it at Phis, and nowhere else.
   // The types presented are the new type of a phi (computed by PhiNode::Value)
   // and the previously computed type, last time the phi was visited.
   //
   // The third argument is upper limit for the saturated value,
   // if the phase wishes to widen the new_type.
   // If the phase is narrowing, the old type provides a lower limit.
   // Caller guarantees that old_type and new_type are no higher than limit_type.
   virtual const Type* saturate(const Type* new_type, const Type* old_type,
                                const Type* limit_type) const
   { ShouldNotCallThis(); return NULL; }
 #ifndef PRODUCT
   void dump_old2new_map() const;
   void dump_new( uint new_lidx ) const;
   void dump_types() const;
   void dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl = true);
   void dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited);
   uint   _count_progress;       // For profiling, count transforms that make progress
   void   set_progress()        { ++_count_progress; assert( allow_progress(),"No progress allowed during verification"); }
   void   clear_progress()      { _count_progress = 0; }
   uint   made_progress() const { return _count_progress; }
   uint   _count_transforms;     // For profiling, count transforms performed
   void   set_transforms()      { ++_count_transforms; }
   void   clear_transforms()    { _count_transforms = 0; }
   uint   made_transforms() const{ return _count_transforms; }
   bool   _allow_progress;      // progress not allowed during verification pass
   void   set_allow_progress(bool allow) { _allow_progress = allow; }
   bool   allow_progress()               { return _allow_progress; }
 #endif
 };
 //------------------------------PhaseValues------------------------------------
 // Phase infrastructure to support values
 class PhaseValues : public PhaseTransform {
 protected:
   NodeHash  _table;             // Hash table for value-numbering
 public:
   PhaseValues( Arena *arena, uint est_max_size );
   PhaseValues( PhaseValues *pt );
   PhaseValues( PhaseValues *ptv, const char *dummy );
   NOT_PRODUCT( ~PhaseValues(); )
   virtual PhaseIterGVN *is_IterGVN() { return 0; }
   // Some Ideal and other transforms delete --> modify --> insert values
   bool   hash_delete(Node *n)     { return _table.hash_delete(n); }
   void   hash_insert(Node *n)     { _table.hash_insert(n); }
   Node  *hash_find_insert(Node *n){ return _table.hash_find_insert(n); }
   Node  *hash_find(const Node *n) { return _table.hash_find(n); }
   // Used after parsing to eliminate values that are no longer in program
   void   remove_useless_nodes(VectorSet &useful) {
     _table.remove_useless_nodes(useful);
     // this may invalidate cached cons so reset the cache
     init_con_caches();
   }
   virtual ConNode* uncached_makecon(const Type* t);  // override from PhaseTransform
   virtual const Type* saturate(const Type* new_type, const Type* old_type,
                                const Type* limit_type) const
   { return new_type; }
 #ifndef PRODUCT
   uint   _count_new_values;     // For profiling, count new values produced
   void    inc_new_values()        { ++_count_new_values; }
   void    clear_new_values()      { _count_new_values = 0; }
   uint    made_new_values() const { return _count_new_values; }
 #endif
 };
 //------------------------------PhaseGVN---------------------------------------
 // Phase for performing local, pessimistic GVN-style optimizations.
 class PhaseGVN : public PhaseValues {
 public:
   PhaseGVN( Arena *arena, uint est_max_size ) : PhaseValues( arena, est_max_size ) {}
   PhaseGVN( PhaseGVN *gvn ) : PhaseValues( gvn ) {}
   PhaseGVN( PhaseGVN *gvn, const char *dummy ) : PhaseValues( gvn, dummy ) {}
   // Return a node which computes the same function as this node, but
   // in a faster or cheaper fashion.
   Node  *transform( Node *n );
   Node  *transform_no_reclaim( Node *n );
   // Check for a simple dead loop when a data node references itself.
   DEBUG_ONLY(void dead_loop_check(Node *n);)
 };
 //------------------------------PhaseIterGVN-----------------------------------
 // Phase for iteratively performing local, pessimistic GVN-style optimizations.
 // and ideal transformations on the graph.
 class PhaseIterGVN : public PhaseGVN {
  private:
   bool _delay_transform;  // When true simply register the node when calling transform
                           // instead of actually optimizing it
   // Idealize old Node 'n' with respect to its inputs and its value
   virtual Node *transform_old( Node *a_node );
   // Subsume users of node 'old' into node 'nn'
   void subsume_node( Node *old, Node *nn );
 protected:
   // Idealize new Node 'n' with respect to its inputs and its value
   virtual Node *transform( Node *a_node );
   // Warm up hash table, type table and initial worklist
   void init_worklist( Node *a_root );
   virtual const Type* saturate(const Type* new_type, const Type* old_type,
                                const Type* limit_type) const;
   // Usually returns new_type.  Returns old_type if new_type is only a slight
   // improvement, such that it would take many (>>10) steps to reach 2**32.
 public:
   PhaseIterGVN( PhaseIterGVN *igvn ); // Used by CCP constructor
   PhaseIterGVN( PhaseGVN *gvn ); // Used after Parser
   PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ); // Used after +VerifyOpto
   virtual PhaseIterGVN *is_IterGVN() { return this; }
   Unique_Node_List _worklist;       // Iterative worklist
   // Given def-use info and an initial worklist, apply Node::Ideal,
   // Node::Value, Node::Identity, hash-based value numbering, Node::Ideal_DU
   // and dominator info to a fixed point.
   void optimize();
   // Register a new node with the iter GVN pass without transforming it.
   // Used when we need to restructure a Region/Phi area and all the Regions
   // and Phis need to complete this one big transform before any other
   // transforms can be triggered on the region.
   // Optional 'orig' is an earlier version of this node.
   // It is significant only for debugging and profiling.
   Node* register_new_node_with_optimizer(Node* n, Node* orig = NULL);
   // Kill a globally dead Node.   It is allowed to have uses which are
   // assumed dead and left 'in limbo'.
   void remove_globally_dead_node( Node *dead );
   // Kill all inputs to a dead node, recursively making more dead nodes.
   // The Node must be dead locally, i.e., have no uses.
   void remove_dead_node( Node *dead ) {
     assert(dead->outcnt() == 0 && !dead->is_top(), "node must be dead");
     remove_globally_dead_node(dead);
   }
   // Add users of 'n' to worklist
   void add_users_to_worklist0( Node *n );
   void add_users_to_worklist ( Node *n );
   // Replace old node with new one.
   void replace_node( Node *old, Node *nn ) {
     add_users_to_worklist(old);
     hash_delete(old); // Yank from hash before hacking edges
     subsume_node(old, nn);
   }
   bool delay_transform() const { return _delay_transform; }
   void set_delay_transform(bool delay) {
     _delay_transform = delay;
   }
   // Clone loop predicates. Defined in loopTransform.cpp.
   Node* clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check);
   // Create a new if below new_entry for the predicate to be cloned
   ProjNode* create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry,
                                         Deoptimization::DeoptReason reason);
 #ifndef PRODUCT
 protected:
   // Sub-quadratic implementation of VerifyIterativeGVN.
   unsigned long _verify_counter;
   unsigned long _verify_full_passes;
   enum { _verify_window_size = 30 };
   Node* _verify_window[_verify_window_size];
   void verify_step(Node* n);
 #endif
 };
 //------------------------------PhaseCCP---------------------------------------
 // Phase for performing global Conditional Constant Propagation.
 // Should be replaced with combined CCP & GVN someday.
 class PhaseCCP : public PhaseIterGVN {
   // Non-recursive.  Use analysis to transform single Node.
   virtual Node *transform_once( Node *n );
 public:
   PhaseCCP( PhaseIterGVN *igvn ); // Compute conditional constants
   NOT_PRODUCT( ~PhaseCCP(); )
   // Worklist algorithm identifies constants
   void analyze();
   // Recursive traversal of program.  Used analysis to modify program.
   virtual Node *transform( Node *n );
   // Do any transformation after analysis
   void          do_transform();
   virtual const Type* saturate(const Type* new_type, const Type* old_type,
                                const Type* limit_type) const;
   // Returns new_type->widen(old_type), which increments the widen bits until
   // giving up with TypeInt::INT or TypeLong::LONG.
   // Result is clipped to limit_type if necessary.
 #ifndef PRODUCT
   static uint _total_invokes;    // For profiling, count invocations
   void    inc_invokes()          { ++PhaseCCP::_total_invokes; }
   static uint _total_constants;  // For profiling, count constants found
   uint   _count_constants;
   void    clear_constants()      { _count_constants = 0; }
   void    inc_constants()        { ++_count_constants; }
   uint    count_constants() const { return _count_constants; }
   static void print_statistics();
 #endif
 };
 //------------------------------PhasePeephole----------------------------------
 // Phase for performing peephole optimizations on register allocated basic blocks.
 class PhasePeephole : public PhaseTransform {
   PhaseRegAlloc *_regalloc;
   PhaseCFG     &_cfg;
   // Recursive traversal of program.  Pure function is unused in this phase
   virtual Node *transform( Node *n );
 public:
   PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg );
   NOT_PRODUCT( ~PhasePeephole(); )
   // Do any transformation after analysis
   void          do_transform();
 #ifndef PRODUCT
   static uint _total_peepholes;  // For profiling, count peephole rules applied
   uint   _count_peepholes;
   void    clear_peepholes()      { _count_peepholes = 0; }
   void    inc_peepholes()        { ++_count_peepholes; }
   uint    count_peepholes() const { return _count_peepholes; }
   static void print_statistics();
 #endif
 };
 #endif // SHARE_VM_OPTO_PHASEX_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/phaseX.hpp@1bd45abaa507 (annotated)

src/share/vm/opto/phaseX.hpp