1.\" Copyright (c) 1985, 1991 Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)ieee.3 6.4 (Berkeley) 5/6/91 33.\" $NetBSD: ieee_test.3,v 1.4 1998/02/05 18:52:07 perry Exp $ 34.\" 35.Dd March 10, 1994 36.Dt IEEE_TEST 3 37.Os 38.Sh NAME 39.Nm logb , 40.Nm scalb , 41.Nm significand 42.Nd IEEE test functions 43.Sh LIBRARY 44.Lb libm 45.Sh SYNOPSIS 46.Fd #include <math.h> 47.Ft double 48.Fn logb "double x" 49.Ft float 50.Fn logbf "float x" 51.Ft double 52.Fn scalb "double x" "double n" 53.Ft float 54.Fn scalbf "float x" "float n" 55.Ft double 56.Fn significand "double x" 57.Ft float 58.Fn significand "float x" 59.Sh DESCRIPTION 60These functions allow users to test conformance to 61.St -ieee754 . 62Their use is not otherwise recommended. 63.Pp 64.Fn logb x 65returns 66.Fa x Ns 's exponent 67.Fa n , 68a signed integer converted to double\-precision floating\-point. 69.Fn logb \*(Pm\*(If 70= +\*(If; 71.Fn logb 0 72= -\*(If with a division by zero exception. 73.Pp 74.Fn scalbn x n 75returns 76.Fa x Ns \(**(2** Ns Fa n ) 77computed by exponent manipulation. 78.Pp 79.Fn significand x 80returns 81.Fa sig , 82where 83.Fa x 84:= 85.Fa sig No \(** 2** Ns Fa n 86with 1 \(<= 87.Fa sig 88< 2. 89.Fn significand x 90is not defined when 91.Fa x 92is 0, \*(Pm\*(If, or \*(Na. 93.Sh SEE ALSO 94.Xr ieee 3 , 95.Xr math 3 96.Sh STANDARDS 97.St -ieee754 98