xref: /dflybsd-src/contrib/openbsd_libm/man/fegetround.3 (revision 4382f29d99a100bd77a81697c2f699c11f6a472a)
1*05a0b428SJohn Marino.\"	$OpenBSD: fegetround.3,v 1.3 2013/06/05 03:40:26 tedu Exp $
2*05a0b428SJohn Marino.\"
3*05a0b428SJohn Marino.\" Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
4*05a0b428SJohn Marino.\"
5*05a0b428SJohn Marino.\" Permission to use, copy, modify, and distribute this software for any
6*05a0b428SJohn Marino.\" purpose with or without fee is hereby granted, provided that the above
7*05a0b428SJohn Marino.\" copyright notice and this permission notice appear in all copies.
8*05a0b428SJohn Marino.\"
9*05a0b428SJohn Marino.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10*05a0b428SJohn Marino.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11*05a0b428SJohn Marino.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12*05a0b428SJohn Marino.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13*05a0b428SJohn Marino.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14*05a0b428SJohn Marino.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15*05a0b428SJohn Marino.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16*05a0b428SJohn Marino.\"
17*05a0b428SJohn Marino.Dd $Mdocdate: June 5 2013 $
18*05a0b428SJohn Marino.Dt FEGETROUND 3
19*05a0b428SJohn Marino.Os
20*05a0b428SJohn Marino.Sh NAME
21*05a0b428SJohn Marino.Nm fegetround ,
22*05a0b428SJohn Marino.Nm fesetround
23*05a0b428SJohn Marino.Nd control floating-point rounding direction modes
24*05a0b428SJohn Marino.Sh SYNOPSIS
25*05a0b428SJohn Marino.In fenv.h
26*05a0b428SJohn Marino.Ft int
27*05a0b428SJohn Marino.Fn fegetround void
28*05a0b428SJohn Marino.Ft int
29*05a0b428SJohn Marino.Fn fesetround "int round"
30*05a0b428SJohn Marino.Sh DESCRIPTION
31*05a0b428SJohn MarinoThese functions provide control of floating-point rounding direction
32*05a0b428SJohn Marinomodes.
33*05a0b428SJohn MarinoThe
34*05a0b428SJohn Marino.Fa round
35*05a0b428SJohn Marinoinput argument is a value specifying a rounding direction mode and
36*05a0b428SJohn Marinocontaining any of the values listed below.
37*05a0b428SJohn Marino.Bl -tag -width ".Dv FE_TOWARDZERO"
38*05a0b428SJohn Marino.It Dv FE_TONEAREST
39*05a0b428SJohn MarinoResults are rounded to the closest representable value.
40*05a0b428SJohn MarinoIf the exact result is exactly half way between two representable
41*05a0b428SJohn Marinovalues, the value whose last binary digit is even (zero) is chosen.
42*05a0b428SJohn MarinoThis is the default mode.
43*05a0b428SJohn Marino.It Dv FE_DOWNWARD
44*05a0b428SJohn MarinoResults are rounded towards negative \*[If].
45*05a0b428SJohn Marino.It Dv FE_UPWARD
46*05a0b428SJohn MarinoResults are rounded towards positive \*[If].
47*05a0b428SJohn Marino.It Dv FE_TOWARDZERO
48*05a0b428SJohn MarinoResults are rounded towards zero.
49*05a0b428SJohn Marino.El
50*05a0b428SJohn Marino.Pp
51*05a0b428SJohn MarinoThe
52*05a0b428SJohn Marino.Fn fegetround
53*05a0b428SJohn Marinofunction gets the current rounding direction.
54*05a0b428SJohn Marino.Pp
55*05a0b428SJohn MarinoThe
56*05a0b428SJohn Marino.Fn fesetround
57*05a0b428SJohn Marinofunction establishes the rounding direction represented by
58*05a0b428SJohn Marino.Pa round .
59*05a0b428SJohn MarinoIf the argument is not equal to the value of a rounding direction
60*05a0b428SJohn Marinomacro, the rounding direction is not changed.
61*05a0b428SJohn Marino.Sh RETURN VALUES
62*05a0b428SJohn MarinoThe
63*05a0b428SJohn Marino.Fn fegetround
64*05a0b428SJohn Marinofunction returns the current rounding direction.
65*05a0b428SJohn MarinoThe
66*05a0b428SJohn Marino.Fn fesetround
67*05a0b428SJohn Marinofunction return zero on success, and non-zero if an error occurred.
68*05a0b428SJohn Marino.Sh SEE ALSO
69*05a0b428SJohn Marino.Xr feclearexcept 3 ,
70*05a0b428SJohn Marino.Xr feenableexcept 3 ,
71*05a0b428SJohn Marino.Xr fegetenv 3
72*05a0b428SJohn Marino.Sh STANDARDS
73*05a0b428SJohn MarinoThe
74*05a0b428SJohn Marino.Fn fegetround
75*05a0b428SJohn Marinoand
76*05a0b428SJohn Marino.Fn fesetround
77*05a0b428SJohn Marinofunctions conform to
78*05a0b428SJohn Marino.St -isoC-99 .
79*05a0b428SJohn Marino.Sh HISTORY
80*05a0b428SJohn MarinoThese functions first appeared in
81*05a0b428SJohn Marino.Ox 5.0 .
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