maxmin(3M)

NAME
     fdim, fdimf, fdiml - positive difference functions

SYNOPSIS
     #include <math.h>

     double fdim(double x, double y);
     float fdimf(float x, float y);
     long double fdiml(long double x, long double y);

DESCRIPTION
     These routines are not available for programs compiled with the O32
     ABI.

     Functions in the standard math library (libm.a) are referred to as -lm
     versions. Those in mathx library (libmx.a) are referred to as -lmx
     versions, and those in the the BSD math library (libm43.a) are
     referred to as -lm43 versions.  These routines are not available in
     the libmx or the libm43 library. These routines are not available in
     the libm43 library.

     The fdim functions return the positive difference value.

NOTES
     Long double operations on this system are only supported in round to
     nearest rounding mode (the default).  The system must be in round to
     nearest rounding mode when calling any of the long double functions,
     or incorrect answers will result.

RETURN VALUES
     The -lm and -lmx versions return the default Quiet NaN and set errno
     to ERANGE on overflow for finite operands x and y and set errno to
     EDOM when a NaN is used as an argument.

SEE ALSO
     math(3M), exp(3M)