1.\"	$OpenBSD: remainder.3,v 1.6 2011/07/07 01:34:52 martynas Exp $
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30.\"     from: @(#)ieee.3	6.4 (Berkeley) 5/6/91
31.\" $FreeBSD: src/lib/msun/man/remainder.3,v 1.6 2008/03/30 20:48:02 das Exp $
32.\"
33.Dd $Mdocdate: July 7 2011 $
34.Dt REMAINDER 3
35.Os
36.Sh NAME
37.Nm remainder ,
38.Nm remainderf ,
39.Nm remainderl ,
40.Nm remquo ,
41.Nm remquof ,
42.Nm remquol
43.Nd minimal residue functions
44.Sh SYNOPSIS
45.In math.h
46.Ft double
47.Fn remainder "double x" "double y"
48.Ft float
49.Fn remainderf "float x" "float y"
50.Ft long double
51.Fn remainderl "long double x" "long double y"
52.Ft double
53.Fn remquo "double x" "double y" "int *quo"
54.Ft float
55.Fn remquof "float x" "float y" "int *quo"
56.Ft long double
57.Fn remquol "long double x" "long double y" "int *quo"
58.Sh DESCRIPTION
59.Fn remainder ,
60.Fn remainderf ,
61.Fn remainderl ,
62.Fn remquo ,
63.Fn remquof ,
64and
65.Fn remquol
66return the remainder
67.Fa r
68:=
69.Fa x
70\-
71.Fa n\(**y
72where
73.Fa n
74is the integer nearest the exact value of
75.Bk -words
76.Fa x Ns / Ns Fa y ;
77.Ek
78moreover if
79.Pf \*(Ba Fa n
80\-
81.Sm off
82.Fa x No / Fa y No \*(Ba
83.Sm on
84=
851/2
86then
87.Fa n
88is even.
89Consequently
90the remainder is computed exactly and
91.Sm off
92.Pf \*(Ba Fa r No \*(Ba
93.Sm on
94\*(Le
95.Sm off
96.Pf \*(Ba Fa y No \*(Ba/2 .
97.Sm on
98But attempting to take the remainder when
99.Fa y
100is 0 or
101.Fa x
102is \*(Pm\*(If is an invalid operation that produces a \*(Na.
103.Pp
104The
105.Fn remquo ,
106.Fn remquof
107and
108.Fn remquol
109functions also store the last
110.Va k
111bits of
112.Fa n
113in the location pointed to by
114.Fa quo ,
115provided that
116.Fa n
117exists.
118The number of bits
119.Va k
120is platform-specific, but is guaranteed to be at least 3.
121.Sh SEE ALSO
122.Xr fmod 3 ,
123.Xr nextafter 3
124.Sh STANDARDS
125The
126.Fn remainder ,
127.Fn remainderf ,
128.Fn remainderl ,
129.Fn remquo ,
130.Fn remquof ,
131and
132.Fn remquol
133routines conform to
134.St -isoC-99 .
135The remainder is as defined in
136.St -ieee754 .
137.Pp
138.Fn drem
139and
140.Fn dremf
141are deprecated aliases for
142.Fn remainder
143and
144.Fn remainderf ,
145respectively.
146.Sh HISTORY
147The
148.Fn remainder
149and
150.Fn remainderf
151functions appeared in
152.Bx 4.3
153and
154.Nx 1.2 ,
155respectively.
156The
157.Fn remquo
158and
159.Fn remquof
160functions were added in
161.Ox 4.4 .
162