source: svn/trunk/newcon3bcm2_21bu/dta/src/bootloader/rsa/mp2_addmul.c

/***************************************************************************
 *     Copyright (c) 2002-2009, Broadcom Corporation
 *     All Rights Reserved
 *     Confidential Property of Broadcom Corporation
 *
 *  THIS SOFTWARE MAY ONLY BE USED SUBJECT TO AN EXECUTED SOFTWARE LICENSE
 *  AGREEMENT  BETWEEN THE USER AND BROADCOM.  YOU HAVE NO RIGHT TO USE OR
 *  EXPLOIT THIS MATERIAL EXCEPT SUBJECT TO THE TERMS OF SUCH AN AGREEMENT.
 *
 * Filename: mp2_addmul.c
 *
 ***************************************************************************/
#include "mp2.h"

/*
 * w = (w + c + x * y) / RADIX; 
 * c = (w + c + x * y) % RADIX;
 */
void addmul(u32 *w, u32 *c, u32 x, u32 y)
{ 
        register u32 lx = x; 
        register u32 ly = y; 
        register u32 x1 = x & RADIXROOTM; 
        register u32 y1 = y & RADIXROOTM; 
        register u32 cc = (*c) + x1 * y1;

        x1 = x1 * (ly >>= NBITSH) + y1 * (lx >>= NBITSH) + (cc >> NBITSH); 
        cc = (cc & RADIXROOTM) + ((x1 & RADIXROOTM) << NBITSH) + *w; 
        *w = ly * lx + (x1 >> NBITSH) + (cc >> NBITS); 
        *c = (cc & RADIXM); 
        
        return;
}