| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: arith24.h,v 1.2 2000/07/02 15:21:20 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 AUTHORS 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 1.2 2000/07/02 15:21:20 mdw |
| 53 | * Fix licence text. |
| 54 | * |
| 55 | * Revision 1.1 2000/05/21 11:28:30 mdw |
| 56 | * Initial check-in. |
| 57 | * |
| 58 | */ |
| 59 | |
| 60 | #ifndef ARITH24_H |
| 61 | #define ARITH24_H |
| 62 | |
| 63 | #ifdef __cplusplus |
| 64 | extern "C" { |
| 65 | #endif |
| 66 | |
| 67 | /*----- Header files ------------------------------------------------------*/ |
| 68 | |
| 69 | #ifndef BITS_H |
| 70 | # include "bits.h" |
| 71 | #endif |
| 72 | |
| 73 | /*----- Functions provided ------------------------------------------------*/ |
| 74 | |
| 75 | /* --- @inv24@ --- * |
| 76 | * |
| 77 | * Arguments: @uint24 x@ = a number to invert |
| 78 | * |
| 79 | * Returns: The multiplicative inverse %$x^{-1}$% of %$x$% (mod |
| 80 | * %$2^{24}$%, if %$x$% is odd, or zero if %$x$% is even (and |
| 81 | * hence uninvertible). |
| 82 | * |
| 83 | * Use: Computes multiplicative inverses mod %$2^{24}$%. |
| 84 | */ |
| 85 | |
| 86 | extern uint24 inv24(uint24 /*x*/); |
| 87 | |
| 88 | /*----- That's all, folks -------------------------------------------------*/ |
| 89 | |
| 90 | #ifdef __cplusplus |
| 91 | } |
| 92 | #endif |
| 93 | |
| 94 | #endif |