1.\" Copyright (c) 2003 Mike Barcroft <mike@FreeBSD.org> 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.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.Dd January 26, 2005 26.Dt FPCLASSIFY 3 27.Os 28.Sh NAME 29.Nm fpclassify , isfinite , isinf , isnan , isnormal 30.Nd "classify a floating-point number" 31.Sh LIBRARY 32.Lb libm 33.Sh SYNOPSIS 34.In math.h 35.Ft int 36.Fn fpclassify "real-floating x" 37.Ft int 38.Fn isfinite "real-floating x" 39.Ft int 40.Fn isinf "real-floating x" 41.Ft int 42.Fn isnan "real-floating x" 43.Ft int 44.Fn isnormal "real-floating x" 45.Sh DESCRIPTION 46The 47.Fn fpclassify 48macro takes an argument of 49.Fa x 50and returns one of the following manifest constants. 51.Bl -tag -width ".Dv FP_SUBNORMAL" 52.It Dv FP_INFINITE 53Indicates that 54.Fa x 55is an infinite number. 56.It Dv FP_NAN 57Indicates that 58.Fa x 59is not a number (NaN). 60.It Dv FP_NORMAL 61Indicates that 62.Fa x 63is a normalized number. 64.It Dv FP_SUBNORMAL 65Indicates that 66.Fa x 67is a denormalized number. 68.It Dv FP_ZERO 69Indicates that 70.Fa x 71is zero (0 or \-0). 72.El 73.Pp 74The 75.Fn isfinite 76macro returns a non-zero value if and only if its argument has 77a finite (zero, subnormal, or normal) value. 78The 79.Fn isinf , 80.Fn isnan , 81and 82.Fn isnormal 83macros return non-zero if and only if 84.Fa x 85is an infinity, NaN, 86or a non-zero normalized number, respectively. 87.Pp 88The symbol 89.Fn isnanf 90is provided as an alias to 91.Fn isnan 92for compatibility, and its use is deprecated. 93Similarly, 94.Fn finite 95and 96.Fn finitef 97are deprecated versions of 98.Fn isfinite . 99.Sh SEE ALSO 100.Xr isgreater 3 , 101.Xr math 3 , 102.Xr signbit 3 103.Sh STANDARDS 104The 105.Fn fpclassify , 106.Fn isfinite , 107.Fn isinf , 108.Fn isnan , 109and 110.Fn isnormal 111macros conform to 112.St -isoC-99 . 113.Sh HISTORY 114The 115.Fn fpclassify , 116.Fn isfinite , 117.Fn isinf , 118.Fn isnan , 119and 120.Fn isnormal 121macros were added in 122.Fx 5.1 . 123.Bx 3 124introduced 125.Fn isinf 126and 127.Fn isnan 128functions, which accepted 129.Vt double 130arguments; these have been superseded by the macros 131described above. 132