xref: /freebsd/lib/msun/man/remainder.3 (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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28.Dd March 30, 2008
29.Dt REMAINDER 3
30.Os
31.Sh NAME
32.Nm remainder ,
33.Nm remainderf ,
34.Nm remainderl ,
35.Nm remquo ,
36.Nm remquof ,
37.Nm remquol
38.Nd minimal residue functions
39.Sh LIBRARY
40.Lb libm
41.Sh SYNOPSIS
42.In math.h
43.Ft double
44.Fn remainder "double x" "double y"
45.Ft float
46.Fn remainderf "float x" "float y"
47.Ft long double
48.Fn remainderl "long double x" "long double y"
49.Ft double
50.Fn remquo "double x" "double y" "int *quo"
51.Ft float
52.Fn remquof "float x" "float y" "int *quo"
53.Ft long double
54.Fn remquol "long double x" "long double y" "int *quo"
55.Sh DESCRIPTION
56.Fn remainder ,
57.Fn remainderf ,
58.Fn remainderl ,
59.Fn remquo ,
60.Fn remquof ,
61and
62.Fn remquol
63return the remainder
64.Fa r
65:=
66.Fa x
67\-
68.Fa n\(**y
69where
70.Fa n
71is the integer nearest the exact value of
72.Bk -words
73.Fa x Ns / Ns Fa y ;
74.Ek
75moreover if
76.Pf \*(Ba Fa n
77\-
78.Sm off
79.Fa x No / Fa y No \*(Ba
80.Sm on
81=
821/2
83then
84.Fa n
85is even.
86Consequently
87the remainder is computed exactly and
88.Sm off
89.Pf \*(Ba Fa r No \*(Ba
90.Sm on
91\*(Le
92.Sm off
93.Pf \*(Ba Fa y No \*(Ba/2 .
94.Sm on
95But attempting to take the remainder when
96.Fa y
97is 0 or
98.Fa x
99is \*(Pm\*(If is an invalid operation that produces a \*(Na.
100.Pp
101The
102.Fn remquo ,
103.Fn remquof ,
104and
105.Fn remquol
106functions also store the last
107.Va k
108bits of
109.Fa n
110in the location pointed to by
111.Fa quo ,
112provided that
113.Fa n
114exists.
115The number of bits
116.Va k
117is platform-specific, but is guaranteed to be at least 3.
118.Sh SEE ALSO
119.Xr fmod 3 ,
120.Xr ieee 3 ,
121.Xr math 3
122.Sh STANDARDS
123The
124.Fn remainder ,
125.Fn remainderf ,
126.Fn remainderl ,
127.Fn remquo ,
128.Fn remquof ,
129and
130.Fn remquol
131routines conform to
132.St -isoC-99 .
133The remainder is as defined in
134.St -ieee754 .
135.Sh HISTORY
136The
137.Fn remainder
138and
139.Fn remainderf
140functions appeared in
141.Bx 4.3
142and
143.Fx 2.0 ,
144respectively.
145The
146.Fn remquo
147and
148.Fn remquof
149functions were added in
150.Fx 6.0 ,
151and
152.Fn remainderl
153and
154.Fn remquol
155were added in
156.Fx 8.0 .
157