1.\" 2.\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for 3.\" permission to reproduce portions of its copyrighted documentation. 4.\" Original documentation from The Open Group can be obtained online at 5.\" http://www.opengroup.org/bookstore/. 6.\" 7.\" The Institute of Electrical and Electronics Engineers and The Open 8.\" Group, have given us permission to reprint portions of their 9.\" documentation. 10.\" 11.\" In the following statement, the phrase ``this text'' refers to portions 12.\" of the system documentation. 13.\" 14.\" Portions of this text are reprinted and reproduced in electronic form 15.\" in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition, 16.\" Standard for Information Technology -- Portable Operating System 17.\" Interface (POSIX), The Open Group Base Specifications Issue 6, 18.\" Copyright (C) 2001-2004 by the Institute of Electrical and Electronics 19.\" Engineers, Inc and The Open Group. In the event of any discrepancy 20.\" between these versions and the original IEEE and The Open Group 21.\" Standard, the original IEEE and The Open Group Standard is the referee 22.\" document. The original Standard can be obtained online at 23.\" http://www.opengroup.org/unix/online.html. 24.\" 25.\" This notice shall appear on any product containing this material. 26.\" 27.\" The contents of this file are subject to the terms of the 28.\" Common Development and Distribution License (the "License"). 29.\" You may not use this file except in compliance with the License. 30.\" 31.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 32.\" or http://www.opensolaris.org/os/licensing. 33.\" See the License for the specific language governing permissions 34.\" and limitations under the License. 35.\" 36.\" When distributing Covered Code, include this CDDL HEADER in each 37.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE. 38.\" If applicable, add the following below this CDDL HEADER, with the 39.\" fields enclosed by brackets "[]" replaced with your own identifying 40.\" information: Portions Copyright [yyyy] [name of copyright owner] 41.\" 42.\" 43.\" Copyright (c) 1992, X/Open Company Limited. All Rights Reserved. 44.\" Copyright (c) 2001, The IEEE and The Open Group. All Rights Reserved. 45.\" Portions Copyright (c) 2006, Sun Microsystems, Inc. All Rights Reserved. 46.\" Portions Copyright 2019 Garrett D'Amore <garrett@damore.org> 47.Dd Jul 05, 2019 48.Dt SCALB 3M 49.Os 50.Sh NAME 51.Nm scalb , 52.Nm scalbf , 53.Nm scalbl 54.Nd load exponent of a radix-independent floating-point number 55.Sh SYNOPSIS 56.Ic c99 Oo Ar flag Ns ... Oc Ar file Ns ... Fl lm Op Ar library Ns ... 57.Pp 58.In math.h 59. 60.Ft double 61.Fo scalb 62.Fa "double x" 63.Fa "double n" 64.Fc 65. 66.Ft float 67.Fo scalbf 68.Fa "float x" 69.Fa "float n" 70.Fc 71. 72.Ft "long double" 73.Fo scalbl 74.Fa "long double x" 75.Fa "long double n" 76.Fc 77. 78.Sh DESCRIPTION 79These functions compute 80.Fa x No * Va r Ns No ^ Ns Fa n , 81where 82.Va r 83is the radix of the machine's floating point arithmetic. 84When 85.Va r 86is 2, 87.Fn scalb 88is equivalent to 89.Xr ldexp 3M . 90The value of 91.Va r 92is 93.Dv FLT_RADIX 94which is 95defined in 96.In float.h . 97.Sh RETURN VALUES 98Upon successful completion, the 99.Fn scalb 100function returns 101.Fa x No * Va r Ns No ^ Ns Fa n . 102.Pp 103If 104.Fa x 105or 106.Fa n 107is 108.Sy NaN , 109a 110.Sy NaN 111is returned. 112.Lp 113If 114.Fa n 115is 0, 116.Fa x 117is returned. 118.Lp 119If 120.Fa x 121is 122.Sy \(+-Inf 123and 124.Fa n 125is not 126.Sy \(miInf , 127.Fa x 128is returned. 129.Lp 130If 131.Fa x 132is \(+-0 and 133.Fa n 134is not 135.Sy +Inf , 136.Fa x 137is returned. 138.Lp 139If 140.Fa x 141is \(+-0 and 142.Fa n 143is 144.Sy +Inf , 145a domain error occurs and a 146.Sy NaN 147is returned. 148.Lp 149If 150.Fa x 151is 152.Sy \(+-Inf 153and 154Fa n 155is 156.Sy \(miInf , 157a domain error occurs and a 158.Sy NaN 159is returned. 160.Lp 161If the result would cause an overflow, a range error occurs and 162.Dv \(+-HUGE_VAL 163(according to the sign of 164.Fa x ) 165is returned. 166.Lp 167For exceptional cases, 168.Xr matherr 3M 169tabulates the values to be returned by 170.Fn scalb 171as specified by SVID3 and XPG3. 172See 173.Xr standards 5 . 174. 175.Sh ERRORS 176. 177These functions will fail if: 178. 179.Bl -tag -width Sy 180.It Sy Domain Error 181If 182.Fa x 183is 0 and 184.Fa n 185is 186.Sy +Inf , 187or 188.Fa x 189is 190.Sy Inf 191and 192.Fa n 193is 194.Sy \(miInf . 195.Lp 196If the integer expression 197.Po Va math_errhandling No & Dv MATH_ERREXCEPT Pc 198.\" (\fBmath_errhandling\fR & \fBMATH_ERREXCEPT\fR) 199is non-zero, then the invalid floating-point exception is raised. 200. 201.It Sy Range Error 202The result would overflow. 203.Lp 204If the integer expression 205.Po Va math_errhandling No & Dv MATH_ERREXCEPT Pc 206is non-zero, then the overflow floating-point exception is raised. 207.El 208. 209.Sh USAGE 210An application wanting to check for exceptions should call 211.Fn feclearexcept FE_ALL_EXCEPT 212before calling these functions. 213On return, if 214.Fn fetestexcept "FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW" 215is non-zero, an exception has been raised. 216An application should either examine the return value or check the 217floating point exception flags to detect exceptions. 218. 219.Lp 220. 221These functions are 222.Sy Obsolete . 223The 224.Xr scalbln 3M , 225.Xr scalblnf 3M , 226or 227.Xr scalblnl 3M 228functions should be used instead. 229. 230.Sh MT-LEVEL 231. 232.Sy MT-Safe . 233. 234.Sh INTERFACE STABILITY 235. 236The 237.Fn scalb 238function is 239.Sy Obsolete Standard . 240The 241.Fn scalbf 242and 243.Fn scalbl 244functions are 245.Sy Obsolete Committed . 246. 247.Sh SEE ALSO 248. 249.Xr math.h 3HEAD , 250.Xr feclearexcept 3M , 251.Xr fetestexcept 3M , 252.Xr ilogb 3M , 253.Xr ldexp 3M , 254.Xr logb 3M , 255.Xr matherr 3M , 256.Xr scalbln 3M , 257.Xr attributes 5 , 258.Xr standards 5 259