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 1.8 2002/02/08 01:28:24 ross Exp $ 34.\" 35.Dd March 10, 1994 36.Dt IEEE_TEST 3 37.Os 38.Sh NAME 39.Nm logb , 40.Nm logbf , 41.Nm scalb , 42.Nm scalbf , 43.Nm significand , 44.Nm significandf 45.Nd IEEE test functions 46.Sh LIBRARY 47.Lb libm 48.Sh SYNOPSIS 49.Fd #include \*[Lt]math.h\*[Gt] 50.Ft double 51.Fn logb "double x" 52.Ft float 53.Fn logbf "float x" 54.Ft double 55.Fn scalb "double x" "double n" 56.Ft float 57.Fn scalbf "float x" "float n" 58.Ft double 59.Fn significand "double x" 60.Ft float 61.Fn significandf "float x" 62.Sh DESCRIPTION 63These functions allow users to test conformance to 64.St -ieee754 . 65Their use is not otherwise recommended. 66.Pp 67.Fn logb x 68returns 69.Fa x Ns 's exponent 70.Fa n , 71a signed integer converted to double\-precision floating\-point. 72.Fn logb \*(Pm\*(If 73= +\*(If; 74.Fn logb 0 75= -\*(If with a division by zero exception. 76.Pp 77.Fn scalbn x n 78returns 79.Fa x Ns \(**(2** Ns Fa n ) 80computed by exponent manipulation. 81.Pp 82.Fn significand x 83returns 84.Fa sig , 85where 86.Fa x 87:= 88.Fa sig No \(** 2** Ns Fa n 89with 1 \*[Le] 90.Fa sig 91\*[Lt] 2. 92.Fn significand x 93is not defined when 94.Fa x 95is 0, \*(Pm\*(If, or \*(Na. 96.Sh SEE ALSO 97.Xr ieee 3 , 98.Xr math 3 99.Sh STANDARDS 100.St -ieee754 101