$NetBSD: signbit.3,v 1.2 2004/01/15 20:31:40 wiz Exp $

Copyright (c) 2003 The NetBSD Foundation, Inc.
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This code is derived from software contributed to The NetBSD Foundation
by Klaus Klein.

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.Dd October 29, 2003 .Dt SIGNBIT 3 .Os .Sh NAME .Nm signbit .Nd test sign .Sh LIBRARY .Lb libc .Sh SYNOPSIS n math.h .Ft int .Fn signbit "real-floating x" .Sh DESCRIPTION The .Fn signbit macro determines whether the sign of its argument value .Fa 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. .Ss IEEE754 The sign is determined for all values, including infinities, zeroes, and NaNs .Ss VAX The sign is determined for finites, true zeros, and dirty zeroes; for ROPs the sign is reported negative. .Sh RETURN VALUES The .Fn signbit macro returns a non-zero value if the sign of its value .Fa x is negative. Otherwise 0 is returned. .Sh ERRORS No errors are defined. .Sh SEE ALSO .Xr fpclassify 3 , .Xr isfinite 3 , .Xr isnormal 3 , .Xr math 3 .Sh STANDARDS The .Fn signbit macro conforms to .St -isoC-99 .