signbit — test sign of a real floating point number
#include <math.h>
int
signbit( |
X) ; |
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Note |
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Compile with |
`signbit' is a generic macro which can work on all real floating-point types. It returns a non-zero value if the value of X has its sign bit set.
This is not the same as `x < 0.0', because IEEE 754 floating point allows zero to be signed. The comparison `−0.0 < 0.0' is false, but `signbit (−0.0)' will return a non-zero value.
C99. This function is defined in IEC 559 (and the appendix with recommended functions in IEEE 754/IEEE 854).
This page is part of release 2.73 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.
Copyright 2002 Walter Harms (walter.harmsinformatik.uni-oldenburg.de) Distributed under GPL Based on glibc infopages |