1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the American National Standards Committee X3, on Information 6.\" Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" @(#)ldexp.3 8.2 (Berkeley) 4/19/94 37.\" $FreeBSD$ 38.\" 39.Dd April 19, 1994 40.Dt LDEXP 3 41.Os 42.Sh NAME 43.Nm ldexp 44.Nd multiply floating-point number by integral power of 2 45.Sh SYNOPSIS 46.Fd #include <math.h> 47.Ft double 48.Fn ldexp "double x" "int exp" 49.Sh DESCRIPTION 50The 51.Fn ldexp 52function multiplies a floating-point number by an integral 53power of 2. 54.Sh RETURN VALUES 55The 56.Fn ldexp 57function returns the value of 58.Fa x 59times 2 raised to the power 60.Fa exp . 61.Pp 62If the resultant value would cause an overflow, 63the global variable 64.Va errno 65is set to 66.Er ERANGE 67and the value 68.Dv HUGE 69is returned. 70.Sh SEE ALSO 71.Xr frexp 3 , 72.Xr math 3 , 73.Xr modf 3 74.Sh STANDARDS 75The 76.Fn ldexp 77function conforms to 78.St -ansiC . 79