NAME

isgreater, isgreaterequal, isless, islessequal, islessgreater, isunordered —

compare two floating-point numbers

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <math.h>

int
isgreater(real-floating x, real-floating y);

int
isgreaterequal(real-floating x, real-floating y);

int
isless(real-floating x, real-floating y);

int
islessequal(real-floating x, real-floating y);

int
islessgreater(real-floating x, real-floating y);

int
isunordered(real-floating x, real-floating y);

DESCRIPTION

Each of the macros isgreater(), isgreaterequal(), isless(), islessequal(), and islessgreater() take arguments x and y and return a non-zero value if and only if its nominal relation on x and y is true. These macros always return zero if either argument is not a number (NaN), but unlike the corresponding C operators, they never raise a floating point exception.

The isunordered() macro takes arguments x and y and returns non-zero if and only if any of x or y are NaNs. For any pair of floating-point values, one of the relationships (less, greater, equal, unordered) holds.

STANDARDS

The isgreater(), isgreaterequal(), isless(), islessequal(), islessgreater(), and isunordered() macros conform to ISO/IEC 9899:1999 (“ISO C99”).

HISTORY

The relational macros described above first appeared in FreeBSD 5.1.