3 * $Id: exp.c,v 1.1 2001/06/16 13:00:59 mdw Exp $
5 * Generalized exponentiation
7 * (c) 2001 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.1 2001/06/16 13:00:59 mdw
34 * New generic exponentation code. Includes sliding-window simultaneous
39 /*----- Header files ------------------------------------------------------*/
41 #define EXP_TYPE /* Hack */
44 /*----- Main code ---------------------------------------------------------*/
46 /* --- @exp_simulnext@ --- *
48 * Arguments: @exp_simul *e@ = pointer to state structure
49 * @size_t x@ = a current accumulator
51 * Returns: The next column of bits.
53 * Use: Scans the next column of bits for a simultaneous
57 size_t exp_simulnext(exp_simul
*e
, size_t x
)
61 /* --- Move to the next word along --- */
65 for (i
= 0; i
< e
->n
; i
++)
66 e
->s
[i
].w
= e
->o
< e
->s
[i
].len ? e
->s
[i
].v
[e
->o
] : 0;
70 /* --- Scan out a column of bits --- */
72 for (i
= 0; i
< e
->n
; i
++) {
73 x
= (x
<< 1) | ((e
->s
[i
].w
>> (MPW_BITS
- 1)) & 1u);
80 /*----- That's all, folks -------------------------------------------------*/