/*******************************************************************************
 *  shift48.c - Shift a 48 bit number left or right.
 *
 *  Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/ 
 * 
 *  Redistribution and use in source and binary forms, with or without 
 *  modification, are permitted provided that the following conditions 
 *  are met:
 *
 *    Redistributions of source code must retain the above copyright 
 *    notice, this list of conditions and the following disclaimer.
 *
 *    Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the   
 *    distribution.
 *
 *    Neither the name of Texas Instruments Incorporated nor the names of
 *    its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
 *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 ******************************************************************************/

#include <inttypes.h>
#include "emeter-toolkit.h"

void shift48(int16_t x[3], int how_far)
{
#if !defined(__MSP430__)
    int64_t tmp;
#endif

    if (how_far < 0)
    {
        while (how_far++)
        {
#if defined(__GNUC__)  &&  defined(__MSP430__)
            __asm__ __volatile__ (
                " rra 4(%[x]) \n"
                " rrc 2(%[x]) \n"
                " rrc 0(%[x]) \n"
                : [x] "+r"(x)
                : );
#else
            tmp = x[2];
            tmp = tmp << 16;
            tmp |= x[1];
            tmp = tmp << 16;
            tmp |= x[0];
            tmp >>= 1;
            x[2] = (tmp >> 32) & 0xFFFF;
            x[1] = (tmp >> 16) & 0xFFFF;
            x[0] = tmp & 0xFFFF;
#endif
        }
    }
    else
    {
        while (how_far--)
        {
#if defined(__GNUC__)  &&  defined(__MSP430__)
            __asm__ __volatile__ (
                " rla 0(%[x]) \n"
                " rlc 2(%[x]) \n"
                " rlc 4(%[x]) \n"
                : [x] "+r"(x)
                : );
#else
            tmp = x[2];
            tmp = tmp << 16;
            tmp |= x[1];
            tmp = tmp << 16;
            tmp |= x[0];
            tmp <<= 1;
            x[2] = (tmp >> 32) & 0xFFFF;
            x[1] = (tmp >> 16) & 0xFFFF;
            x[0] = tmp & 0xFFFF;
#endif
        }
    }
}
