| SIGNBIT(3) | Library Functions Manual | SIGNBIT(3) |
signbit — test
sign
Standard C Library (libc, -lc)
#include
<math.h>
int
signbit(real-floating
x);
The
signbit()
macro determines whether the sign of its argument value
x is negative. An argument represented in a format
wider than its semantic type is converted to its semantic type first. The
determination is then based on the type of the argument.
The sign is determined for all values, including infinities, zeroes, and NaNs
The sign is determined for finites, true zeros, and dirty zeroes; for ROPs the sign is reported negative.
The signbit() macro returns a non-zero
value if the sign of its value x is negative.
Otherwise 0 is returned.
No errors are defined.
The signbit() macro conforms to
ISO/IEC 9899:1999
(“ISO C99”).
| October 29, 2003 | NetBSD 11.0 |