Name
signbit — test sign of a real floating point
number
Synopsis
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Note |
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Compile with −std=c99; link with
−lm.
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DESCRIPTION
`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.
CONFORMING TO
C99. This function is defined in IEC 559 (and the appendix
with recommended functions in IEEE 754/IEEE 854).
SEE ALSO
copysign(3)
Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
Distributed under GPL
Based on glibc infopages
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