xref: /freebsd/lib/msun/man/remainder.3 (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
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31.Dd March 30, 2008
32.Dt REMAINDER 3
33.Os
34.Sh NAME
35.Nm remainder ,
36.Nm remainderf ,
37.Nm remainderl ,
38.Nm remquo ,
39.Nm remquof ,
40.Nm remquol
41.Nd minimal residue functions
42.Sh LIBRARY
43.Lb libm
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 ieee 3 ,
124.Xr math 3
125.Sh STANDARDS
126The
127.Fn remainder ,
128.Fn remainderf ,
129.Fn remainderl ,
130.Fn remquo ,
131.Fn remquof ,
132and
133.Fn remquol
134routines conform to
135.St -isoC-99 .
136The remainder is as defined in
137.St -ieee754 .
138.Sh HISTORY
139The
140.Fn remainder
141and
142.Fn remainderf
143functions appeared in
144.Bx 4.3
145and
146.Fx 2.0 ,
147respectively.
148The
149.Fn remquo
150and
151.Fn remquof
152functions were added in
153.Fx 6.0 ,
154and
155.Fn remainderl
156and
157.Fn remquol
158were added in
159.Fx 8.0 .
160