diff options
Diffstat (limited to 'man3/signbit.3')
| -rw-r--r-- | man3/signbit.3 | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/man3/signbit.3 b/man3/signbit.3 index 5dddad6..ad7a1f4 100644 --- a/man3/signbit.3 +++ b/man3/signbit.3 @@ -7,7 +7,7 @@ .\" .\" Based on glibc infopages, copyright Free Software Foundation .\" -.TH signbit 3 2023-07-20 "Linux man-pages 6.05.01" +.TH signbit 3 2023-10-31 "Linux man-pages 6.7" .SH NAME signbit \- test sign of a real floating-point number .SH LIBRARY @@ -16,15 +16,15 @@ Math library .SH SYNOPSIS .nf .B "#include <math.h>" -.PP +.P .BI "int signbit(" x ");" .fi -.PP +.P .RS -4 Feature Test Macro Requirements for glibc (see .BR feature_test_macros (7)): .RE -.PP +.P .BR signbit (): .nf _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L @@ -35,7 +35,7 @@ is a generic macro which can work on all real floating-point types. It returns a nonzero value if the value of .I x has its sign bit set. -.PP +.P This is not the same as .IR "x < 0.0" , because IEEE 754 floating point allows zero to be signed. @@ -44,7 +44,7 @@ The comparison is false, but .I signbit(\-0.0) will return a nonzero value. -.PP +.P NaNs and infinities have a sign bit. .SH RETURN VALUE The @@ -68,12 +68,11 @@ T{ .BR signbit () T} Thread safety MT-Safe .TE -.sp 1 .SH STANDARDS C11, POSIX.1-2008. .SH HISTORY POSIX.1-2001, C99. -.PP +.P This function is defined in IEC 559 (and the appendix with recommended functions in IEEE 754/IEEE 854). .SH SEE ALSO |