fillbytes.c

Go to the documentation of this file.

/* @(#)fillbytes.c  1.18 10/08/21 Copyright 1987, 1995-2010 J. Schilling */
/*
 *  fill memory with data
 *
 *  Copyright (c) 1987, 1995-2010 J. Schilling
 */
/*
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * See the file CDDL.Schily.txt in this distribution for details.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file CDDL.Schily.txt from this distribution.
 */
 
#include <schily/standard.h>
#include <schily/align.h>
#include <schily/types.h>
#include <schily/schily.h>
 
#define DO8(a)  a; a; a; a; a; a; a; a;
 
#define cval    ((char)lval)
 
/*
 * fillbytes(to, cnt, val) is the same as memset(to, val, cnt)
 */
#ifdef  PROTOTYPES
EXPORT char *
fillbytes(void *tov, ssize_t cnt, char val)
#else
EXPORT char *
fillbytes(tov, cnt, val)
    void    *tov;
    ssize_t cnt;
    char    val;
#endif
{
    register char   *to = (char *)tov;
    register ssize_t n;
    register long   lval;
 
    /*
     * If we change cnt to be unsigned, check for == instead of <=
     */
    if ((n = cnt) <= 0)
        return (to);
 
    lval = val & 0xFF;
 
    /*
     * Assign byte-wise until properly aligned for a long pointer.
     */
    while (--n >= 0 && !laligned(to)) {
        *to++ = cval;
    }
    n++;
 
    if (n >= (ssize_t)(8 * sizeof (long))) {
        register ssize_t rem = n % (8 * sizeof (long));
 
        lval |= (lval<<8);
        lval |= (lval<<16);
#if SIZE_LONG > SIZE_INT
        lval |= (lval<<32);
#endif
 
        n /= (8 * sizeof (long));
        {
            register long *tol = (long *)to;
 
            do {
                DO8 (*tol++ = lval);
            } while (--n > 0);
 
            to = (char *)tol;
        }
        n = rem;
 
        if (n >= 8) {
            n -= 8;
            do {
                DO8 (*to++ = cval);
            } while ((n -= 8) >= 0);
            n += 8;
        }
        if (n > 0) do {
            *to++ = cval;
        } while (--n > 0);
        return (to);
    }
    if (n > 0) do {
        *to++ = cval;
    } while (--n > 0);
    return (to);
}