hash.h

   1 /***************************************************************************
   2                           hash.h  -  Hash related definitions
   3                              -------------------
   4     begin                : Sun Sep 28 2007
   5     copyright            : (C) 2007 by Maurizio Monge
   6     email                : monge@linuz.sns.it
   7  ***************************************************************************/
   8
   9 /***************************************************************************
  10  *                                                                         *
  11  *   This program is free software; you can redistribute it and/or modify  *
  12  *   it under the terms of the GNU General Public License as published by  *
  13  *   the Free Software Foundation; either version 2 of the License, or     *
  14  *   (at your option) any later version.                                   *
  15  *                                                                         *
  16  ***************************************************************************/
  17
  18 #ifndef __HASH_H__
  19 #define __HASH_H__
  20
  21 #include "utils.h"
  22
  23 /* Yes, 96 bits hash keys.
  24    the 'index' field is used as index in the hashtable,
  25    the 'check' field to check the indexed position.
  26    Now, i don't want event to think about possible key collisions :) */
  27 class PACKED HashKey
  28 {
  29 public:
  30     union
  31     {
  32         uint64_t check;
  33         struct {
  34             uint32_t check_lo;
  35             uint32_t check_hi;
  36         };
  37     };
  38     uint32_t index;
  39
  40     HashKey(){}
  41     HashKey(uint64_t c, uint32_t i = 0) :
  42             check(c), index(i) {}
  43     HashKey(uint32_t ch, uint32_t cl, uint32_t i) :
  44             check_lo(cl), check_hi(ch), index(i) {}
  45
  46     HashKey operator^(const HashKey& h)  const  {
  47         return HashKey(check ^ h.check, index ^ h.index);    }
  48     const HashKey& operator^=(const HashKey& h)    {
  49         check ^= h.check;
  50         index ^= h.index;
  51         return *this;
  52     }
  53     bool operator==(const HashKey& h) const  {
  54         return (check == h.check) && (index == h.index);    }
  55     bool operator!=(const HashKey& h) const   {
  56         return (check != h.check) || (index != h.index);    }
  57     bool operator<(const HashKey& h) const  {
  58         return check<h.check ? true :
  59                 (check==h.check && index<h.index) ? true :
  60                 false; }
  61     void print() const;
  62     char* to_string(char*) const;
  63 };
  64
  65 /* An entry in the hashtable */
  66 class PACKED HashEntry
  67 {
  68 public:
  69     /* field to verify the entry against a position */
  70     uint64_t check;
  71     int16_t depth;
  72     uint8_t is_old : 1;
  73     uint8_t no_good_moves : 1;
  74     uint16_t best_mv : 14;
  75     int16_t lo;
  76     int16_t up;
  77
  78     int16_t lower(){ return lo; }
  79     int16_t upper(){ return up; }
  80 };
  81
  82 #endif //__HASH_H__