unfl.c

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/*  unfl.c    CCMATH mathematics library source code.
 *
 *  Copyright (C)  2000   Daniel A. Atkinson    All rights reserved.
 *  This code may be redistributed under the terms of the GNU library
 *  public license (LGPL). ( See the lgpl.license file for details.)
 * ------------------------------------------------------------------------
 */
static unsigned int a = 69069U, c = 244045795U;
static unsigned int s, h, sbuf[256];
double unfl(void)
{
    int i;
 
    i = (int)(s >> 24);
    s = sbuf[i];
    h = a * h + c;
    sbuf[i] = h;
    return s * 2.328306436538696e-10;
}
 
void setunfl(unsigned int k)
{
    int j;
 
    for (h = k, j = 0; j <= 256; ++j) {
        h = a * h + c;
        if (j < 256)
            sbuf[j] = h;
        else
            s = h;
    }
}