/* 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 */