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 1.10 2003/08/07 16:44:48 agc Exp $ 30.\" 31.Dd March 10, 1994 32.Dt IEEE_TEST 3 33.Os 34.Sh NAME 35.Nm logb , 36.Nm logbf , 37.Nm scalb , 38.Nm scalbf , 39.Nm significand , 40.Nm significandf 41.Nd IEEE test functions 42.Sh LIBRARY 43.Lb libm 44.Sh SYNOPSIS 45.In math.h 46.Ft double 47.Fn logb "double x" 48.Ft float 49.Fn logbf "float x" 50.Ft double 51.Fn scalb "double x" "double n" 52.Ft float 53.Fn scalbf "float x" "float n" 54.Ft double 55.Fn significand "double x" 56.Ft float 57.Fn significandf "float x" 58.Sh DESCRIPTION 59These functions allow users to test conformance to 60.St -ieee754 . 61Their use is not otherwise recommended. 62.Pp 63.Fn logb x 64returns 65.Fa x Ns 's exponent 66.Fa n , 67a signed integer converted to double\-precision floating\-point. 68.Fn logb \*(Pm\*(If 69= +\*(If; 70.Fn logb 0 71= -\*(If with a division by zero exception. 72.Pp 73.Fn scalbn x n 74returns 75.Fa x Ns \(**(2** Ns Fa n ) 76computed by exponent manipulation. 77.Pp 78.Fn significand x 79returns 80.Fa sig , 81where 82.Fa x 83:= 84.Fa sig No \(** 2** Ns Fa n 85with 1 \*[Le] 86.Fa sig 87\*[Lt] 2. 88.Fn significand x 89is not defined when 90.Fa x 91is 0, \*(Pm\*(If, or \*(Na. 92.Sh SEE ALSO 93.Xr ieee 3 , 94.Xr math 3 95.Sh STANDARDS 96.St -ieee754 97