diff options
Diffstat (limited to 'man3/scalb.3')
| -rw-r--r-- | man3/scalb.3 | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/man3/scalb.3 b/man3/scalb.3 new file mode 100644 index 0000000..5513a27 --- /dev/null +++ b/man3/scalb.3 @@ -0,0 +1,197 @@ +'\" 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 +.\" +.TH scalb 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +scalb, scalbf, scalbl \- multiply floating-point number +by integral power of radix (OBSOLETE) +.SH LIBRARY +Math library +.RI ( libm ", " \-lm ) +.SH SYNOPSIS +.nf +.B #include <math.h> +.PP +.BI "[[deprecated]] double scalb(double " x ", double " exp ); +.BI "[[deprecated]] float scalbf(float " x ", float " exp ); +.BI "[[deprecated]] long double scalbl(long double " x ", long double " exp ); +.fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.PP +.BR scalb (): +.nf + _XOPEN_SOURCE >= 500 +.\" || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED + || /* Since glibc 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE +.fi +.PP +.BR scalbf (), +.BR scalbl (): +.nf + _XOPEN_SOURCE >= 600 + || /* Since glibc 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE +.fi +.SH DESCRIPTION +These functions multiply their first argument +.I x +by +.B FLT_RADIX +(probably 2) +to the power of +.IR exp , +that is: +.PP +.nf + x * FLT_RADIX ** exp +.fi +.PP +The definition of +.B FLT_RADIX +can be obtained by including +.IR <float.h> . +.\" not in /usr/include but in a gcc lib +.SH RETURN VALUE +On success, these functions return +.I x +* +.B FLT_RADIX +** +.IR exp . +.PP +If +.I x +or +.I exp +is a NaN, a NaN is returned. +.PP +If +.I x +is positive infinity (negative infinity), +and +.I exp +is not negative infinity, +positive infinity (negative infinity) is returned. +.PP +If +.I x +is +0 (\-0), and +.I exp +is not positive infinity, +0 (\-0) is returned. +.PP +If +.I x +is zero, and +.I exp +is positive infinity, +a domain error occurs, and +a NaN is returned. +.PP +If +.I x +is an infinity, +and +.I exp +is negative infinity, +a domain error occurs, and +a NaN is returned. +.PP +If the result overflows, +a range error occurs, +and the functions return +.BR HUGE_VAL , +.BR HUGE_VALF , +or +.BR HUGE_VALL , +respectively, with a sign the same as +.IR x . +.PP +If the result underflows, +a range error occurs, +and the functions return zero, with a sign the same as +.IR x . +.SH ERRORS +See +.BR math_error (7) +for information on how to determine whether an error has occurred +when calling these functions. +.PP +The following errors can occur: +.TP +Domain error: \fIx\fP is 0, and \fIexp\fP is positive infinity, \ +or \fIx\fP is positive infinity and \fIexp\fP is negative infinity \ +and the other argument is not a NaN +.I errno +is set to +.BR EDOM . +An invalid floating-point exception +.RB ( FE_INVALID ) +is raised. +.TP +Range error, overflow +.I errno +is set to +.BR ERANGE . +An overflow floating-point exception +.RB ( FE_OVERFLOW ) +is raised. +.TP +Range error, underflow +.I errno +is set to +.BR ERANGE . +An underflow floating-point exception +.RB ( FE_UNDERFLOW ) +is raised. +.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 scalb (), +.BR scalbf (), +.BR scalbl () +T} Thread safety MT-Safe +.TE +.sp 1 +.SH STANDARDS +None. +.SH HISTORY +.TP +.BR scalb () +4.3BSD. +Obsolescent in POSIX.1-2001; +Removed in POSIX.1-2008, +recommending the use of +.BR scalbln (3), +.BR scalblnf (3), +or +.BR scalblnl (3) +instead. +.\" Looking at header files: scalbf() is present on the +.\" BSDs, Tru64, HP-UX 11, Irix 6.5; scalbl() is on HP-UX 11 and Tru64. +.SH BUGS +Before glibc 2.20, +.\" https://www.sourceware.org/bugzilla/show_bug.cgi?id=6803 +.\" https://www.sourceware.org/bugzilla/show_bug.cgi?id=6804 +these functions did not set +.I errno +for domain and range errors. +.SH SEE ALSO +.BR ldexp (3), +.BR scalbln (3) |