New, improved fmod.c

This commit is contained in:
ceriel 1993-08-31 10:54:08 +00:00
parent a37e49b619
commit 668b3fc2d8

View file

@ -1,33 +1,34 @@
/*
* (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
* Author: Hans van Eck
*/
/* fmod function */
/* Author Robert R. Hall (hall@crach.cts.com) */
/* $Header$ */
#include <math.h>
#include <errno.h>
double
fmod(double x, double y)
{
double val;
double frac;
(fmod)(double x, double y)
{ /* compute fmod(x, y) */
double t;
int n, neg;
int ychar, xchar;
if (y == 0) {
if (y == 0.0) {
errno = EDOM;
return 0;
return 0.0;
}
frac = modf( x / y, &val);
/* fmod(finite, finite) */
if (y < 0.0) y = -y;
if (x < 0.0) x = -x, neg = 1;
else neg = 0;
t = frexp(y, &ychar);
/* substract |y| until |x| < |y| */
return frac * y;
/*
val = x / y;
if (val > LONG_MIN && val < LONG_MAX) {
long i = val;
return x - i * y;
t = frexp(x, &xchar);
for (n = xchar - ychar; 0 <= n; --n) {
/* try to substract |y|*2^n */
t = ldexp(y, n);
if (t <= x) x -= t;
}
*/
return (neg ? -x : x);
}