xref: /freebsd/share/man/man3/Q_FRAWMASK.3 (revision 2f513db7)
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26.\" $FreeBSD$
27.\"
28.Dd July 8, 2018
29.Dt Q_FRAWMASK 3
30.Os
31.Sh NAME
32.Nm Q_FRAWMASK ,
33.Nm Q_GFRAW ,
34.Nm Q_GFABSVAL ,
35.Nm Q_GFVAL ,
36.Nm Q_SFVAL
37.Nd fixed-point math functions which manipulate the fractional data bits
38.Sh SYNOPSIS
39.In sys/qmath.h
40.Ft ITYPE
41.Fn Q_FRAWMASK "QTYPE q"
42.Ft ITYPE
43.Fn Q_GFRAW "QTYPE q"
44.Ft ITYPE
45.Fn Q_GFABSVAL "QTYPE q"
46.Ft ITYPE
47.Fn Q_GFVAL "QTYPE q"
48.Ft QTYPE
49.Fn Q_SFVAL "QTYPE q" "ITYPE fv"
50.Sh DESCRIPTION
51.Fn Q_FRAWMASK
52returns a
53.Fa q Ns -specific
54bit mask for
55.Fa q Ap s
56fractional data bits.
57.Pp
58.Fn Q_GFRAW
59returns
60.Fa q Ap s
61raw masked fractional data bits.
62.Pp
63.Fn Q_GFABSVAL
64and
65.Fn Q_GFVAL
66return the absolute and real values of
67.Fa q Ap s
68fractional data bits respectively.
69.Pp
70.Fn Q_SFVAL
71sets
72.Fa q Ap s
73fractional data bits to the value
74.Fa fv .
75.Pp
76All of those functions operate on
77the following data types:
78.Vt s8q_t ,
79.Vt u8q_t ,
80.Vt s16q_t ,
81.Vt u16q_t ,
82.Vt s32q_t ,
83.Vt u32q_t ,
84.Vt s64q_t ,
85and
86.Vt u64q_t ,
87which are referred to generically as
88.Fa QTYPE .
89The
90.Fa ITYPE
91refers to the
92.Xr stdint 7
93integer types.
94.Pp
95For more details, see
96.Xr qmath 3 .
97.Sh RETURN VALUES
98.Fn Q_FRAWMASK ,
99.Fn Q_GFRAW ,
100.Fn Q_GFABSVAL
101and
102.Fn Q_GFVAL
103return their respective values as integers of the same underlying ITYPE as
104.Fa q .
105.Pp
106.Fn Q_SFVAL
107returns the value of
108.Fa q
109post set.
110.Sh SEE ALSO
111.Xr errno 2 ,
112.Xr qmath 3 ,
113.Xr stdint 7
114.Sh HISTORY
115The
116.Xr qmath 3
117functions first appeared in
118.Fx 13.0 .
119.Sh AUTHORS
120.An -nosplit
121The
122.Xr qmath 3
123functions and this manual page were written by
124.An Lawrence Stewart Aq Mt lstewart@FreeBSD.org
125and sponsored by Netflix, Inc.
126