mdw@git.distorted.org.uk Git - storin/blob - arith24.h

   1 /* -*-c-*-
   2  *
   3  * $Id: arith24.h,v 1.1 2000/05/21 11:28:30 mdw Exp $
   4  *
   5  * Arithmetic mod %$2^{24}$%
   6  *
   7  * (c) 2000 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * Copyright (c) 2000 Mark Wooding
  13  * All rights reserved.
  14  *
  15  * Redistribution and use in source and binary forms, with or without
  16  * modification, are permitted provided that the following conditions are
  17  * met:
  18  *
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  *
  22  * 2, Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  *
  26  * 3. The name of the authors may not be used to endorse or promote
  27  *    products derived from this software without specific prior written
  28  *    permission.
  29  *
  30  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  31  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  32  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  33  * NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  34  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  35  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  36  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  38  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  39  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  40  * POSSIBILITY OF SUCH DAMAGE.
  41  *
  42  * Instead of accepting the above terms, you may redistribute and/or modify
  43  * this software under the terms of either the GNU General Public License,
  44  * or the GNU Library General Public License, published by the Free
  45  * Software Foundation; either version 2 of the License, or (at your
  46  * option) any later version.
  47  */
  48
  49 /*----- Revision history --------------------------------------------------*
  50  *
  51  * $Log: arith24.h,v $
  52  * Revision 1.1  2000/05/21 11:28:30  mdw
  53  * Initial check-in.
  54  *
  55  */
  56
  57 #ifndef ARITH24_H
  58 #define ARITH24_H
  59
  60 #ifdef __cplusplus
  61   extern "C" {
  62 #endif
  63
  64 /*----- Header files ------------------------------------------------------*/
  65
  66 #ifndef BITS_H
  67 #  include "bits.h"
  68 #endif
  69
  70 /*----- Functions provided ------------------------------------------------*/
  71
  72 /* --- @inv24@ --- *
  73  *
  74  * Arguments:   @uint24 x@ = a number to invert
  75  *
  76  * Returns:     The multiplicative inverse %$x^{-1}$% of %$x$% (mod
  77  *              %$2^{24}$%, if %$x$% is odd, or zero if %$x$% is even (and
  78  *              hence uninvertible).
  79  *
  80  * Use:         Computes multiplicative inverses mod %$2^{24}$%.
  81  */
  82
  83 extern uint24 inv24(uint24 /*x*/);
  84
  85 /*----- That's all, folks -------------------------------------------------*/
  86
  87 #ifdef __cplusplus
  88   }
  89 #endif
  90
  91 #endif