jdk8-mips64-public/hotspot: src/share/vm/opto/chaitin.hpp@98cb887364d3 (annotated)

src/share/vm/opto/chaitin.hpp@98cb887364d3 (annotated)

src/share/vm/opto/chaitin.hpp

Fri, 27 Feb 2009 13:27:09 -0800

author: twisti
date: Fri, 27 Feb 2009 13:27:09 -0800
changeset 1040: 98cb887364d3
parent 1001: 91263420e1c6
child 1063: 7bb995fbd3c0
permissions: -rw-r--r--

6810672: Comment typos
Summary: I have collected some typos I have found while looking at the code.
Reviewed-by: kvn, never

 /*
  * Copyright 1997-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 class LoopTree;
 class MachCallNode;
 class MachSafePointNode;
 class Matcher;
 class PhaseCFG;
 class PhaseLive;
 class PhaseRegAlloc;
 class   PhaseChaitin;
 #define OPTO_DEBUG_SPLIT_FREQ  BLOCK_FREQUENCY(0.001)
 #define OPTO_LRG_HIGH_FREQ     BLOCK_FREQUENCY(0.25)
 //------------------------------LRG--------------------------------------------
 // Live-RanGe structure.
 class LRG : public ResourceObj {
 public:
   enum { SPILL_REG=29999 };     // Register number of a spilled LRG
   double _cost;                 // 2 for loads/1 for stores times block freq
   double _area;                 // Sum of all simultaneously live values
   double score() const;         // Compute score from cost and area
   double _maxfreq;              // Maximum frequency of any def or use
   Node *_def;                   // Check for multi-def live ranges
 #ifndef PRODUCT
   GrowableArray<Node*>* _defs;
 #endif
   uint _risk_bias;              // Index of LRG which we want to avoid color
   uint _copy_bias;              // Index of LRG which we want to share color
   uint _next;                   // Index of next LRG in linked list
   uint _prev;                   // Index of prev LRG in linked list
 private:
   uint _reg;                    // Chosen register; undefined if mask is plural
 public:
   // Return chosen register for this LRG.  Error if the LRG is not bound to
   // a single register.
   OptoReg::Name reg() const { return OptoReg::Name(_reg); }
   void set_reg( OptoReg::Name r ) { _reg = r; }
 private:
   uint _eff_degree;             // Effective degree: Sum of neighbors _num_regs
 public:
   int degree() const { assert( _degree_valid, "" ); return _eff_degree; }
   // Degree starts not valid and any change to the IFG neighbor
   // set makes it not valid.
   void set_degree( uint degree ) { _eff_degree = degree; debug_only(_degree_valid = 1;) }
   // Made a change that hammered degree
   void invalid_degree() { debug_only(_degree_valid=0;) }
   // Incrementally modify degree.  If it was correct, it should remain correct
   void inc_degree( uint mod ) { _eff_degree += mod; }
   // Compute the degree between 2 live ranges
   int compute_degree( LRG &l ) const;
 private:
   RegMask _mask;                // Allowed registers for this LRG
   uint _mask_size;              // cache of _mask.Size();
 public:
   int compute_mask_size() const { return _mask.is_AllStack() ? 65535 : _mask.Size(); }
   void set_mask_size( int size ) {
     assert((size == 65535) || (size == (int)_mask.Size()), "");
     _mask_size = size;
     debug_only(_msize_valid=1;)
     debug_only( if( _num_regs == 2 && !_fat_proj ) _mask.VerifyPairs(); )
   }
   void compute_set_mask_size() { set_mask_size(compute_mask_size()); }
   int mask_size() const { assert( _msize_valid, "mask size not valid" );
                           return _mask_size; }
   // Get the last mask size computed, even if it does not match the
   // count of bits in the current mask.
   int get_invalid_mask_size() const { return _mask_size; }
   const RegMask &mask() const { return _mask; }
   void set_mask( const RegMask &rm ) { _mask = rm; debug_only(_msize_valid=0;)}
   void AND( const RegMask &rm ) { _mask.AND(rm); debug_only(_msize_valid=0;)}
   void SUBTRACT( const RegMask &rm ) { _mask.SUBTRACT(rm); debug_only(_msize_valid=0;)}
   void Clear()   { _mask.Clear()  ; debug_only(_msize_valid=1); _mask_size = 0; }
   void Set_All() { _mask.Set_All(); debug_only(_msize_valid=1); _mask_size = RegMask::CHUNK_SIZE; }
   void Insert( OptoReg::Name reg ) { _mask.Insert(reg);  debug_only(_msize_valid=0;) }
   void Remove( OptoReg::Name reg ) { _mask.Remove(reg);  debug_only(_msize_valid=0;) }
   void ClearToPairs() { _mask.ClearToPairs(); debug_only(_msize_valid=0;) }
   // Number of registers this live range uses when it colors
 private:
   uint8 _num_regs;              // 2 for Longs and Doubles, 1 for all else
                                 // except _num_regs is kill count for fat_proj
 public:
   int num_regs() const { return _num_regs; }
   void set_num_regs( int reg ) { assert( _num_regs == reg || !_num_regs, "" ); _num_regs = reg; }
 private:
   // Number of physical registers this live range uses when it colors
   // Architecture and register-set dependent
   uint8 _reg_pressure;
 public:
   void set_reg_pressure(int i)  { _reg_pressure = i; }
   int      reg_pressure() const { return _reg_pressure; }
   // How much 'wiggle room' does this live range have?
   // How many color choices can it make (scaled by _num_regs)?
   int degrees_of_freedom() const { return mask_size() - _num_regs; }
   // Bound LRGs have ZERO degrees of freedom.  We also count
   // must_spill as bound.
   bool is_bound  () const { return _is_bound; }
   // Negative degrees-of-freedom; even with no neighbors this
   // live range must spill.
   bool not_free() const { return degrees_of_freedom() <  0; }
   // Is this live range of "low-degree"?  Trivially colorable?
   bool lo_degree () const { return degree() <= degrees_of_freedom(); }
   // Is this live range just barely "low-degree"?  Trivially colorable?
   bool just_lo_degree () const { return degree() == degrees_of_freedom(); }
   uint   _is_oop:1,             // Live-range holds an oop
          _is_float:1,           // True if in float registers
          _was_spilled1:1,       // True if prior spilling on def
          _was_spilled2:1,       // True if twice prior spilling on def
          _is_bound:1,           // live range starts life with no
                                 // degrees of freedom.
          _direct_conflict:1,    // True if def and use registers in conflict
          _must_spill:1,         // live range has lost all degrees of freedom
     // If _fat_proj is set, live range does NOT require aligned, adjacent
     // registers and has NO interferences.
     // If _fat_proj is clear, live range requires num_regs() to be a power of
     // 2, and it requires registers to form an aligned, adjacent set.
          _fat_proj:1,           //
          _was_lo:1,             // Was lo-degree prior to coalesce
          _msize_valid:1,        // _mask_size cache valid
          _degree_valid:1,       // _degree cache valid
          _has_copy:1,           // Adjacent to some copy instruction
          _at_risk:1;            // Simplify says this guy is at risk to spill
   // Alive if non-zero, dead if zero
   bool alive() const { return _def != NULL; }
   bool is_multidef() const { return _def == NodeSentinel; }
   bool is_singledef() const { return _def != NodeSentinel; }
 #ifndef PRODUCT
   void dump( ) const;
 #endif
 };
 //------------------------------LRG_List---------------------------------------
 // Map Node indices to Live RanGe indices.
 // Array lookup in the optimized case.
 class LRG_List : public ResourceObj {
   uint _cnt, _max;
   uint* _lidxs;
   ReallocMark _nesting;         // assertion check for reallocations
 public:
   LRG_List( uint max );
   uint lookup( uint nidx ) const {
     return _lidxs[nidx];
   }
   uint operator[] (uint nidx) const { return lookup(nidx); }
   void map( uint nidx, uint lidx ) {
     assert( nidx < _cnt, "oob" );
     _lidxs[nidx] = lidx;
   }
   void extend( uint nidx, uint lidx );
   uint Size() const { return _cnt; }
 };
 //------------------------------IFG--------------------------------------------
 //                         InterFerence Graph
 // An undirected graph implementation.  Created with a fixed number of
 // vertices.  Edges can be added & tested.  Vertices can be removed, then
 // added back later with all edges intact.  Can add edges between one vertex
 // and a list of other vertices.  Can union vertices (and their edges)
 // together.  The IFG needs to be really really fast, and also fairly
 // abstract!  It needs abstraction so I can fiddle with the implementation to
 // get even more speed.
 class PhaseIFG : public Phase {
   // Current implementation: a triangular adjacency list.
   // Array of adjacency-lists, indexed by live-range number
   IndexSet *_adjs;
   // Assertion bit for proper use of Squaring
   bool _is_square;
   // Live range structure goes here
   LRG *_lrgs;                   // Array of LRG structures
 public:
   // Largest live-range number
   uint _maxlrg;
   Arena *_arena;
   // Keep track of inserted and deleted Nodes
   VectorSet *_yanked;
   PhaseIFG( Arena *arena );
   void init( uint maxlrg );
   // Add edge between a and b.  Returns true if actually addded.
   int add_edge( uint a, uint b );
   // Add edge between a and everything in the vector
   void add_vector( uint a, IndexSet *vec );
   // Test for edge existance
   int test_edge( uint a, uint b ) const;
   // Square-up matrix for faster Union
   void SquareUp();
   // Return number of LRG neighbors
   uint neighbor_cnt( uint a ) const { return _adjs[a].count(); }
   // Union edges of b into a on Squared-up matrix
   void Union( uint a, uint b );
   // Test for edge in Squared-up matrix
   int test_edge_sq( uint a, uint b ) const;
   // Yank a Node and all connected edges from the IFG.  Be prepared to
   // re-insert the yanked Node in reverse order of yanking.  Return a
   // list of neighbors (edges) yanked.
   IndexSet *remove_node( uint a );
   // Reinsert a yanked Node
   void re_insert( uint a );
   // Return set of neighbors
   IndexSet *neighbors( uint a ) const { return &_adjs[a]; }
 #ifndef PRODUCT
   // Dump the IFG
   void dump() const;
   void stats() const;
   void verify( const PhaseChaitin * ) const;
 #endif
   //--------------- Live Range Accessors
   LRG &lrgs(uint idx) const { assert(idx < _maxlrg, "oob"); return _lrgs[idx]; }
   // Compute and set effective degree.  Might be folded into SquareUp().
   void Compute_Effective_Degree();
   // Compute effective degree as the sum of neighbors' _sizes.
   int effective_degree( uint lidx ) const;
 };
 // TEMPORARILY REPLACED WITH COMMAND LINE FLAG
 //// !!!!! Magic Constants need to move into ad file
 #ifdef SPARC
 //#define FLOAT_PRESSURE 30  /*     SFLT_REG_mask.Size() - 1 */
 //#define INT_PRESSURE   23  /* NOTEMP_I_REG_mask.Size() - 1 */
 #define FLOAT_INCREMENT(regs) regs
 #else
 //#define FLOAT_PRESSURE 6
 //#define INT_PRESSURE   6
 #define FLOAT_INCREMENT(regs) 1
 #endif
 //------------------------------Chaitin----------------------------------------
 // Briggs-Chaitin style allocation, mostly.
 class PhaseChaitin : public PhaseRegAlloc {
   int _trip_cnt;
   int _alternate;
   uint _maxlrg;                 // Max live range number
   LRG &lrgs(uint idx) const { return _ifg->lrgs(idx); }
   PhaseLive *_live;             // Liveness, used in the interference graph
   PhaseIFG *_ifg;               // Interference graph (for original chunk)
   Node_List **_lrg_nodes;       // Array of node; lists for lrgs which spill
   VectorSet _spilled_once;      // Nodes that have been spilled
   VectorSet _spilled_twice;     // Nodes that have been spilled twice
   LRG_List _names;              // Map from Nodes to Live RanGes
   // Union-find map.  Declared as a short for speed.
   // Indexed by live-range number, it returns the compacted live-range number
   LRG_List _uf_map;
   // Reset the Union-Find map to identity
   void reset_uf_map( uint maxlrg );
   // Remove the need for the Union-Find mapping
   void compress_uf_map_for_nodes( );
   // Combine the Live Range Indices for these 2 Nodes into a single live
   // range.  Future requests for any Node in either live range will
   // return the live range index for the combined live range.
   void Union( const Node *src, const Node *dst );
   void new_lrg( const Node *x, uint lrg );
   // Compact live ranges, removing unused ones.  Return new maxlrg.
   void compact();
   uint _lo_degree;              // Head of lo-degree LRGs list
   uint _lo_stk_degree;          // Head of lo-stk-degree LRGs list
   uint _hi_degree;              // Head of hi-degree LRGs list
   uint _simplified;             // Linked list head of simplified LRGs
   // Helper functions for Split()
   uint split_DEF( Node *def, Block *b, int loc, uint max, Node **Reachblock, Node **debug_defs, GrowableArray<uint> splits, int slidx );
   uint split_USE( Node *def, Block *b, Node *use, uint useidx, uint max, bool def_down, bool cisc_sp, GrowableArray<uint> splits, int slidx );
   int clone_projs( Block *b, uint idx, Node *con, Node *copy, uint &maxlrg );
   Node *split_Rematerialize(Node *def, Block *b, uint insidx, uint &maxlrg, GrowableArray<uint> splits,
                             int slidx, uint *lrg2reach, Node **Reachblock, bool walkThru);
   // True if lidx is used before any real register is def'd in the block
   bool prompt_use( Block *b, uint lidx );
   Node *get_spillcopy_wide( Node *def, Node *use, uint uidx );
   // Insert the spill at chosen location.  Skip over any intervening Proj's or
   // Phis.  Skip over a CatchNode and projs, inserting in the fall-through block
   // instead.  Update high-pressure indices.  Create a new live range.
   void insert_proj( Block *b, uint i, Node *spill, uint maxlrg );
   bool is_high_pressure( Block *b, LRG *lrg, uint insidx );
   uint _oldphi;                 // Node index which separates pre-allocation nodes
   Block **_blks;                // Array of blocks sorted by frequency for coalescing
 #ifndef PRODUCT
   bool _trace_spilling;
 #endif
 public:
   PhaseChaitin( uint unique, PhaseCFG &cfg, Matcher &matcher );
   ~PhaseChaitin() {}
   // Convert a Node into a Live Range Index - a lidx
   uint Find( const Node *n ) {
     uint lidx = n2lidx(n);
     uint uf_lidx = _uf_map[lidx];
     return (uf_lidx == lidx) ? uf_lidx : Find_compress(n);
   }
   uint Find_const( uint lrg ) const;
   uint Find_const( const Node *n ) const;
   // Do all the real work of allocate
   void Register_Allocate();
   uint n2lidx( const Node *n ) const { return _names[n->_idx]; }
 #ifndef PRODUCT
   bool trace_spilling() const { return _trace_spilling; }
 #endif
 private:
   // De-SSA the world.  Assign registers to Nodes.  Use the same register for
   // all inputs to a PhiNode, effectively coalescing live ranges.  Insert
   // copies as needed.
   void de_ssa();
   uint Find_compress( const Node *n );
   uint Find( uint lidx ) {
     uint uf_lidx = _uf_map[lidx];
     return (uf_lidx == lidx) ? uf_lidx : Find_compress(lidx);
   }
   uint Find_compress( uint lidx );
   uint Find_id( const Node *n ) {
     uint retval = n2lidx(n);
     assert(retval == Find(n),"Invalid node to lidx mapping");
     return retval;
   }
   // Add edge between reg and everything in the vector.
   // Same as _ifg->add_vector(reg,live) EXCEPT use the RegMask
   // information to trim the set of interferences.  Return the
   // count of edges added.
   void interfere_with_live( uint reg, IndexSet *live );
   // Count register pressure for asserts
   uint count_int_pressure( IndexSet *liveout );
   uint count_float_pressure( IndexSet *liveout );
   // Build the interference graph using virtual registers only.
   // Used for aggressive coalescing.
   void build_ifg_virtual( );
   // Build the interference graph using physical registers when available.
   // That is, if 2 live ranges are simultaneously alive but in their
   // acceptable register sets do not overlap, then they do not interfere.
   uint build_ifg_physical( ResourceArea *a );
   // Gather LiveRanGe information, including register masks and base pointer/
   // derived pointer relationships.
   void gather_lrg_masks( bool mod_cisc_masks );
   // Force the bases of derived pointers to be alive at GC points.
   bool stretch_base_pointer_live_ranges( ResourceArea *a );
   // Helper to stretch above; recursively discover the base Node for
   // a given derived Node.  Easy for AddP-related machine nodes, but
   // needs to be recursive for derived Phis.
   Node *find_base_for_derived( Node **derived_base_map, Node *derived, uint &maxlrg );
   // Set the was-lo-degree bit.  Conservative coalescing should not change the
   // colorability of the graph.  If any live range was of low-degree before
   // coalescing, it should Simplify.  This call sets the was-lo-degree bit.
   void set_was_low();
   // Split live-ranges that must spill due to register conflicts (as opposed
   // to capacity spills).  Typically these are things def'd in a register
   // and used on the stack or vice-versa.
   void pre_spill();
   // Init LRG caching of degree, numregs.  Init lo_degree list.
   void cache_lrg_info( );
   // Simplify the IFG by removing LRGs of low degree with no copies
   void Pre_Simplify();
   // Simplify the IFG by removing LRGs of low degree
   void Simplify();
   // Select colors by re-inserting edges into the IFG.
   // Return TRUE if any spills occurred.
   uint Select( );
   // Helper function for select which allows biased coloring
   OptoReg::Name choose_color( LRG &lrg, int chunk );
   // Helper function which implements biasing heuristic
   OptoReg::Name bias_color( LRG &lrg, int chunk );
   // Split uncolorable live ranges
   // Return new number of live ranges
   uint Split( uint maxlrg );
   // Copy 'was_spilled'-edness from one Node to another.
   void copy_was_spilled( Node *src, Node *dst );
   // Set the 'spilled_once' or 'spilled_twice' flag on a node.
   void set_was_spilled( Node *n );
   // Convert ideal spill-nodes into machine loads & stores
   // Set C->failing when fixup spills could not complete, node limit exceeded.
   void fixup_spills();
   // Post-Allocation peephole copy removal
   void post_allocate_copy_removal();
   Node *skip_copies( Node *c );
   int yank_if_dead( Node *old, Block *current_block, Node_List *value, Node_List *regnd );
   int elide_copy( Node *n, int k, Block *current_block, Node_List &value, Node_List &regnd, bool can_change_regs );
   int use_prior_register( Node *copy, uint idx, Node *def, Block *current_block, Node_List &value, Node_List &regnd );
   bool may_be_copy_of_callee( Node *def ) const;
   // If nreg already contains the same constant as val then eliminate it
   bool eliminate_copy_of_constant(Node* val, Node* n,
                                   Block *current_block, Node_List& value, Node_List &regnd,
                                   OptoReg::Name nreg, OptoReg::Name nreg2);
   // Extend the node to LRG mapping
   void add_reference( const Node *node, const Node *old_node);
 private:
   static int _final_loads, _final_stores, _final_copies, _final_memoves;
   static double _final_load_cost, _final_store_cost, _final_copy_cost, _final_memove_cost;
   static int _conserv_coalesce, _conserv_coalesce_pair;
   static int _conserv_coalesce_trie, _conserv_coalesce_quad;
   static int _post_alloc;
   static int _lost_opp_pp_coalesce, _lost_opp_cflow_coalesce;
   static int _used_cisc_instructions, _unused_cisc_instructions;
   static int _allocator_attempts, _allocator_successes;
 #ifndef PRODUCT
   static uint _high_pressure, _low_pressure;
   void dump() const;
   void dump( const Node *n ) const;
   void dump( const Block * b ) const;
   void dump_degree_lists() const;
   void dump_simplified() const;
   void dump_lrg( uint lidx ) const;
   void dump_bb( uint pre_order ) const;
   // Verify that base pointers and derived pointers are still sane
   void verify_base_ptrs( ResourceArea *a ) const;
   void verify( ResourceArea *a, bool verify_ifg = false ) const;
   void dump_for_spill_split_recycle() const;
 public:
   void dump_frame() const;
   char *dump_register( const Node *n, char *buf  ) const;
 private:
   static void print_chaitin_statistics();
 #endif
   friend class PhaseCoalesce;
   friend class PhaseAggressiveCoalesce;
   friend class PhaseConservativeCoalesce;
 };

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/chaitin.hpp@98cb887364d3 (annotated)

src/share/vm/opto/chaitin.hpp