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diff --git a/man/man3/ldexp.3 b/man/man3/ldexp.3 new file mode 100644 index 0000000..5e00270 --- /dev/null +++ b/man/man3/ldexp.3 @@ -0,0 +1,131 @@ +'\" t +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk +.\" <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) +.\" Modified 2004-10-31 by aeb +.\" +.TH ldexp 3 2024-05-02 "Linux man-pages (unreleased)" +.SH NAME +ldexp, ldexpf, ldexpl \- multiply floating-point number by integral power of 2 +.SH LIBRARY +Math library +.RI ( libm ", " \-lm ) +.SH SYNOPSIS +.nf +.B #include <math.h> +.P +.BI "double ldexp(double " x ", int " exp ); +.BI "float ldexpf(float " x ", int " exp ); +.BI "long double ldexpl(long double " x ", int " exp ); +.fi +.P +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.P +.BR ldexpf (), +.BR ldexpl (): +.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 return the result of multiplying the floating-point number +.I x +by 2 raised to the power +.IR exp . +.SH RETURN VALUE +On success, these functions return +.IR "x * (2\[ha]exp)" . +.P +If +.I exp +is zero, then +.I x +is returned. +.P +If +.I x +is a NaN, +a NaN is returned. +.P +If +.I x +is positive infinity (negative infinity), +positive infinity (negative infinity) is returned. +.P +If the result underflows, +a range error occurs, +and zero is returned. +.P +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 . +.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 +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 ldexp (), +.BR ldexpf (), +.BR ldexpl () +T} Thread safety MT-Safe +.TE +.SH STANDARDS +C11, POSIX.1-2008. +.SH HISTORY +C99, POSIX.1-2001. +.P +The variant returning +.I double +also conforms to +SVr4, 4.3BSD, C89. +.SH SEE ALSO +.BR frexp (3), +.BR modf (3), +.BR scalbln (3) |