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/*

 * Copyright (c) 2001-2004 Jakub Jermar

 * Copyright (c) 2008 Jiri Svoboda

 * All rights reserved.

 *

 * 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.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.

 */

/** @addtogroup generic

 * @{

 */

/**

 * @file

 * @brief   Memory string operations.

 *

 * This file provides architecture independent functions to manipulate blocks of

 * memory. These functions are optimized as much as generic functions of this

 * type can be. However, architectures are free to provide even more optimized

 * versions of these functions.

 */

#include <memstr.h>

#include <arch/types.h>

#include <align.h>

/** Copy block of memory.

 *

 * Copy cnt bytes from src address to dst address.  The copying is done

 * word-by-word and then byte-by-byte.  The source and destination memory areas

 * cannot overlap.

 *

 * @param src       Source address to copy from.

 * @param dst       Destination address to copy to.

 * @param cnt       Number of bytes to copy.

 *

 * @return      Destination address.

 */

void *_memcpy(void *dst, const void *src, size_t cnt)

{

    unsigned int i, j;

    if (ALIGN_UP((uintptr_t) src, sizeof(unative_t)) != (uintptr_t) src ||

        ALIGN_UP((uintptr_t) dst, sizeof(unative_t)) != (uintptr_t) dst) {

        for (i = 0; i < cnt; i++)

            ((uint8_t *) dst)[i] = ((uint8_t *) src)[i];

    } else {

        for (i = 0; i < cnt / sizeof(unative_t); i++)

            ((unative_t *) dst)[i] = ((unative_t *) src)[i];

        for (j = 0; j < cnt % sizeof(unative_t); j++)

            ((uint8_t *)(((unative_t *) dst) + i))[j] =

                ((uint8_t *)(((unative_t *) src) + i))[j];

    }

    return (char *) dst;

}

/** Move memory block with possible overlapping.

 *

 * Copy cnt bytes from src address to dst address. The source and destination

 * memory areas may overlap.

 *

 * @param src       Source address to copy from.

 * @param dst       Destination address to copy to.

 * @param cnt       Number of bytes to copy.

 *

 * @return      Destination address.

 */

void *memmove(void *dst, const void *src, size_t n)

{

    const uint8_t *sp;

    uint8_t *dp;

    /* Nothing to do? */

    if (src == dst)

        return dst;

    /* Non-overlapping? */

    if (dst >= src + n || src >= dst + n) {

        return memcpy(dst, src, n);

    }

    /* Which direction? */

    if (src > dst) {

        /* Forwards. */

        sp = src;

        dp = dst;

        while (n-- != 0)

            *dp++ = *sp++;

    } else {

        /* Backwards. */

        sp = src + (n - 1);

        dp = dst + (n - 1);

        while (n-- != 0)

            *dp-- = *sp--;

    }

    return dst;

}

/** Fill block of memory

 *

 * Fill cnt bytes at dst address with the value x.  The filling is done

 * byte-by-byte.

 *

 * @param dst       Destination address to fill.

 * @param cnt       Number of bytes to fill.

 * @param x     Value to fill.

 *

 */

void _memsetb(void *dst, size_t cnt, uint8_t x)

{

    unsigned int i;

    uint8_t *p = (uint8_t *) dst;

    for (i = 0; i < cnt; i++)

        p[i] = x;

}

/** Fill block of memory.

 *

 * Fill cnt words at dst address with the value x.  The filling is done

 * word-by-word.

 *

 * @param dst       Destination address to fill.

 * @param cnt       Number of words to fill.

 * @param x     Value to fill.

 *

 */

void _memsetw(void *dst, size_t cnt, uint16_t x)

{

    unsigned int i;

    uint16_t *p = (uint16_t *) dst;

    for (i = 0; i < cnt; i++)

        p[i] = x;  

}

/** @}

 */