chiark - git - mdw - catacomb/blob - karatsuba.h

   1 /* -*-c-*-
   2  *
   3  * $Id: karatsuba.h,v 1.1 2000/06/17 11:42:11 mdw Exp $
   4  *
   5  * Macros for Karatsuba functions
   6  *
   7  * (c) 2000 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: karatsuba.h,v $
  33  * Revision 1.1  2000/06/17 11:42:11  mdw
  34  * Moved the Karatsuba macros into a separate file for better sharing.
  35  * Fixed some comments.
  36  *
  37  */
  38
  39 #ifndef CATACOMB_MPX_KMAC_H
  40 #define CATACOMB_MPX_KMAC_H
  41
  42 #ifdef __cplusplus
  43   extern "C" {
  44 #endif
  45
  46 /*----- Header files ------------------------------------------------------*/
  47
  48 #ifndef CATACOMB_MPW_H
  49 #  include "mpw.h"
  50 #endif
  51
  52 /*----- Macros provided ---------------------------------------------------*/
  53
  54 #define UADD(dv, av, avl) do {                                          \
  55   mpw *_dv = (dv);                                                      \
  56   const mpw *_av = (av), *_avl = (avl);                                 \
  57   mpw _c = 0;                                                           \
  58                                                                         \
  59   while (_av < _avl) {                                                  \
  60     mpw _a, _b;                                                         \
  61     mpd _x;                                                             \
  62     _a = *_av++;                                                        \
  63     _b = *_dv;                                                          \
  64     _x = (mpd)_a + (mpd)_b + _c;                                        \
  65     *_dv++ = MPW(_x);                                                   \
  66     _c = _x >> MPW_BITS;                                                \
  67   }                                                                     \
  68   while (_c) {                                                          \
  69     mpd _x = (mpd)*_dv + (mpd)_c;                                       \
  70     *_dv++ = MPW(_x);                                                   \
  71     _c = _x >> MPW_BITS;                                                \
  72   }                                                                     \
  73 } while (0)
  74
  75 #define UADD2(dv, dvl, av, avl, bv, bvl) do {                           \
  76   mpw *_dv = (dv), *_dvl = (dvl);                                       \
  77   const mpw *_av = (av), *_avl = (avl);                                 \
  78   const mpw *_bv = (bv), *_bvl = (bvl);                                 \
  79   mpw _c = 0;                                                           \
  80                                                                         \
  81   while (_av < _avl || _bv < _bvl) {                                    \
  82     mpw _a, _b;                                                         \
  83     mpd _x;                                                             \
  84     _a = (_av < _avl) ? *_av++ : 0;                                     \
  85     _b = (_bv < _bvl) ? *_bv++ : 0;                                     \
  86     _x = (mpd)_a + (mpd)_b + _c;                                        \
  87     *_dv++ = MPW(_x);                                                   \
  88     _c = _x >> MPW_BITS;                                                \
  89   }                                                                     \
  90   *_dv++ = _c;                                                          \
  91   while (_dv < _dvl)                                                    \
  92     *_dv++ = 0;                                                         \
  93 } while (0)
  94
  95 #define USUB(dv, av, avl) do {                                          \
  96   mpw *_dv = (dv);                                                      \
  97   const mpw *_av = (av), *_avl = (avl);                                 \
  98   mpw _c = 0;                                                           \
  99                                                                         \
 100   while (_av < _avl) {                                                  \
 101     mpw _a, _b;                                                         \
 102     mpd _x;                                                             \
 103     _a = *_av++;                                                        \
 104     _b = *_dv;                                                          \
 105     _x = (mpd)_b - (mpd)_a - _c;                                        \
 106     *_dv++ = MPW(_x);                                                   \
 107     if (_x >> MPW_BITS)                                                 \
 108       _c = 1;                                                           \
 109     else                                                                \
 110       _c = 0;                                                           \
 111   }                                                                     \
 112   while (_c) {                                                          \
 113     mpd _x = (mpd)*_dv - (mpd)_c;                                       \
 114     *_dv++ = MPW(_x);                                                   \
 115     if (_x >> MPW_BITS)                                                 \
 116       _c = 1;                                                           \
 117     else                                                                \
 118       _c = 0;                                                           \
 119   }                                                                     \
 120 } while (0)
 121
 122 /*----- That's all, folks -------------------------------------------------*/
 123
 124 #ifdef __cplusplus
 125   }
 126 #endif
 127
 128 #endif