source: trunk/sys/dietlibc/memcpy.c @ 21

/* fast memcpy -- Copyright (C) 2003 Thomas M. Ogrisegg <tom@hi-tek.fnord.at> */

#include <string.h>
#include "dietfeatures.h"
#include "dietstring.h"

void *
memcpy (void *dst, const void *src, size_t n)
{
    void           *res = dst;
    unsigned char  *c1, *c2;
#ifdef WANT_SMALL_STRING_ROUTINES
    c1 = (unsigned char *) dst;
    c2 = (unsigned char *) src;
    while (n--) *c1++ = *c2++;
    return (res);
#else
    int             tmp;
    unsigned long  *lx1 = NULL;
    const unsigned long *lx2 = NULL;

    if (!UNALIGNED(dst, src) && n > sizeof(unsigned long)) {

        if ((tmp = STRALIGN(dst))) {
            c1 = (unsigned char *) dst;
            c2 = (unsigned char *) src;
            while (tmp-- && n--)
                *c1++ = *c2++;
            if (n == (size_t) - 1)
                return (res);
            dst = c1;
            src = c2;
        }

        lx1 = (unsigned long *) dst;
        lx2 = (unsigned long *) src;

        for (; n >= sizeof(unsigned long); n -= sizeof(unsigned long))
            *lx1++ = *lx2++;
    }

    if (n) {
        c1 = (unsigned char *) (lx1?lx1:dst);
        c2 = (unsigned char *) (lx1?lx2:src);
        while (n--)
            *c1++ = *c2++;
    }

    return (res);
#endif
}