SIGNBIT(3)             FreeBSD Library Functions Manual             SIGNBIT(3)

NAME
     signbit - determine whether a floating-point number's sign is negative

LIBRARY
     Math Library (libm, -lm)

SYNOPSIS
     #include <math.h>

     int
     signbit(real-floating x);

DESCRIPTION
     The signbit() macro takes an argument of x and returns non-zero if the
     value of its sign is negative, otherwise 0.

SEE ALSO
     fpclassify(3), math(3)

STANDARDS
     The signbit() macro conforms to ISO/IEC 9899:1999 ("ISO C99").

HISTORY
     The signbit() macro was added in FreeBSD 5.1.

FreeBSD 13.1-RELEASE-p6          July 18, 2004         FreeBSD 13.1-RELEASE-p6