62 lines
1.1 KiB
C
62 lines
1.1 KiB
C
/* 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
|
|
|
|
ANSI_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
|
|
|
|
#ifdef __STDC__
|
|
double fdim(double x, double y)
|
|
#else
|
|
double fdim(x,y)
|
|
double x;
|
|
double y;
|
|
#endif
|
|
{
|
|
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 */
|