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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" from: @(#)ieee.3 6.4 (Berkeley) 5/6/91 29.\" $NetBSD: ieee_test.3,v 1.14 2017/07/03 21:32:50 wiz Exp $ 30.\" 31.Dd August 3, 2011 32.Dt IEEE_TEST 3 33.Os 34.Sh NAME 35.Nm logb , 36.Nm logbf , 37.Nm logbl , 38.Nm scalb , 39.Nm scalbf , 40.Nm significand , 41.Nm significandf 42.Nd IEEE test functions 43.Sh LIBRARY 44.Lb libm 45.Sh SYNOPSIS 46.In math.h 47.Ft double 48.Fn logb "double x" 49.Ft float 50.Fn logbf "float x" 51.Ft long double 52.Fn logbl "long double x" 53.Ft double 54.Fn scalb "double x" "double n" 55.Ft float 56.Fn scalbf "float x" "float n" 57.Ft double 58.Fn significand "double x" 59.Ft float 60.Fn significandf "float x" 61.Sh DESCRIPTION 62These functions allow users to test conformance to 63.St -ieee754 . 64Their use is otherwise not recommended. 65.Pp 66.Fn logb x 67returns 68.Fa x Ns 's exponent 69.Fa n , 70a signed integer converted to double\-precision floating\-point. 71.Fn logb \*(Pm\*(If 72= +\*(If; 73.Fn logb 0 74= -\*(If with a division by zero exception. 75.Pp 76.Fn scalb x n 77returns 78.Fa x Ns \(**(2** Ns Fa n ) 79computed by exponent manipulation. 80.Pp 81.Fn significand x 82returns 83.Fa sig , 84where 85.Fa x 86:= 87.Fa sig No \(** 2** Ns Fa n 88with 1 \*[Le] 89.Fa sig 90< 2. 91.Fn significand x 92is not defined when 93.Fa x 94is 0, \*(Pm\*(If, or \*(Na. 95.Sh SEE ALSO 96.Xr math 3 97.Sh STANDARDS 98.St -ieee754 99