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/* Copyright (C) 2002 by Red Hat, Incorporated. All rights reserved.
*
* Permission to use, copy, modify, and distribute this software
* is freely granted, provided that this notice is preserved.
*/
/*
FUNCTION
<<fdim>>, <<fdimf>>---positive difference
INDEX
fdim
INDEX
fdimf
SYNOPSIS
#include <math.h>
double fdim(double <[x]>, double <[y]>);
float fdimf(float <[x]>, float <[y]>);
DESCRIPTION
The <<fdim>> functions determine the positive difference between their
arguments, returning:
. <[x]> - <[y]> if <[x]> > <[y]>, or
@ifnottex
. +0 if <[x]> <= <[y]>, or
@end ifnottex
@tex
. +0 if <[x]> $\leq$ <[y]>, or
@end tex
. NAN if either argument is NAN.
A range error may occur.
RETURNS
The <<fdim>> functions return the positive difference value.
PORTABILITY
ANSI C, POSIX.
*/
#include "fdlibm.h"
#ifndef _DOUBLE_IS_32BITS
double fdim(double x, double y)
{
int c = __fpclassifyd(x);
if (c == FP_NAN) return(x);
if (__fpclassifyd(y) == FP_NAN) return(y);
if (c == FP_INFINITE)
return HUGE_VAL;
return x > y ? x - y : 0.0;
}
#endif /* _DOUBLE_IS_32BITS */
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