diff options
Diffstat (limited to 'man3/logb.3')
-rw-r--r-- | man3/logb.3 | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/man3/logb.3 b/man3/logb.3 deleted file mode 100644 index 1319d94..0000000 --- a/man3/logb.3 +++ /dev/null @@ -1,142 +0,0 @@ -'\" t -.\" Copyright 2004 Andries Brouwer <aeb@cwi.nl>. -.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk -.\" <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.\" Inspired by a page by Walter Harms created 2002-08-10 -.\" -.TH logb 3 2024-03-12 "Linux man-pages 6.7" -.SH NAME -logb, logbf, logbl \- get exponent of a floating-point value -.SH LIBRARY -Math library -.RI ( libm ", " \-lm ) -.SH SYNOPSIS -.nf -.B #include <math.h> -.P -.BI "double logb(double " x ); -.BI "float logbf(float " x ); -.BI "long double logbl(long double " x ); -.fi -.P -.RS -4 -Feature Test Macro Requirements for glibc (see -.BR feature_test_macros (7)): -.RE -.P -.BR logb (): -.nf - _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L - || _XOPEN_SOURCE >= 500 -.\" || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED - || /* Since glibc 2.19: */ _DEFAULT_SOURCE - || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE -.fi -.P -.BR logbf (), -.BR logbl (): -.nf - _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L - || /* Since glibc 2.19: */ _DEFAULT_SOURCE - || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE -.fi -.SH DESCRIPTION -These functions extract the exponent from the -internal floating-point representation of -.I x -and return it as a floating-point value. -The integer constant -.BR FLT_RADIX , -defined in -.IR <float.h> , -indicates the radix used for the system's floating-point representation. -If -.B FLT_RADIX -is 2, -.BI logb( x ) -is similar to -.BI floor(log2(fabs( x )))\f[R],\f[] -except that the latter may give an incorrect integer -due to intermediate rounding. -.P -If -.I x -is subnormal, -.BR logb () -returns the exponent -.I x -would have if it were normalized. -.SH RETURN VALUE -On success, these functions return the exponent of -.IR x . -.P -If -.I x -is a NaN, -a NaN is returned. -.P -If -.I x -is zero, then a pole error occurs, and the functions return -.RB \- HUGE_VAL , -.RB \- HUGE_VALF , -or -.RB \- HUGE_VALL , -respectively. -.P -If -.I x -is negative infinity or positive infinity, then -positive infinity is returned. -.SH ERRORS -See -.BR math_error (7) -for information on how to determine whether an error has occurred -when calling these functions. -.P -The following errors can occur: -.TP -Pole error: \fIx\fP is 0 -.\" .I errno -.\" is set to -.\" .BR ERANGE . -A divide-by-zero floating-point exception -.RB ( FE_DIVBYZERO ) -is raised. -.P -These functions do not set -.IR errno . -.\" FIXME . Is it intentional that these functions do not set errno? -.\" log(), log2(), log10() do set errno -.\" Bug raised: https://www.sourceware.org/bugzilla/show_bug.cgi?id=6793 -.\" -.SH ATTRIBUTES -For an explanation of the terms used in this section, see -.BR attributes (7). -.TS -allbox; -lbx lb lb -l l l. -Interface Attribute Value -T{ -.na -.nh -.BR logb (), -.BR logbf (), -.BR logbl () -T} Thread safety MT-Safe -.TE -.SH STANDARDS -C11, POSIX.1-2008. -.SH HISTORY -C99, POSIX.1-2001. -.TP -.BR logb () -4.3BSD -(see IEEE.3 in the 4.3BSD manual). -.SH SEE ALSO -.BR ilogb (3), -.BR log (3) |