Changeset View
Changeset View
Standalone View
Standalone View
share/man/man3/Q_SIGNSHFT.3
- This file was added.
.\" | |||||
.\" Copyright (c) 2018 Netflix, Inc. | |||||
.\" All rights reserved. | |||||
.\" | |||||
.\" Redistribution and use in source and binary forms, with or without | |||||
.\" modification, are permitted provided that the following conditions | |||||
.\" are met: | |||||
.\" 1. Redistributions of source code must retain the above copyright | |||||
.\" notice, this list of conditions, and the following disclaimer, | |||||
.\" without modification, immediately at the beginning of the file. | |||||
.\" 2. The name of the author may not be used to endorse or promote products | |||||
.\" derived from this software without specific prior written permission. | |||||
.\" | |||||
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |||||
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |||||
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |||||
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR | |||||
.\" ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |||||
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |||||
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |||||
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |||||
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |||||
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |||||
.\" SUCH DAMAGE. | |||||
.\" | |||||
.\" $FreeBSD$ | |||||
.\" | |||||
.Dd July 8, 2018 | |||||
.Dt Q_SIGNSHFT 3 | |||||
.Os | |||||
.Sh NAME | |||||
.Nm Q_SIGNSHFT , | |||||
.Nm Q_SSIGN , | |||||
.Nm Q_CRAWMASK , | |||||
.Nm Q_SRAWMASK , | |||||
.Nm Q_GCRAW , | |||||
.Nm Q_GCVAL , | |||||
.Nm Q_SCVAL | |||||
.Nd fixed-point math functions which manipulate the control/sign data bits | |||||
.Sh SYNOPSIS | |||||
.In sys/qmath.h | |||||
.Ft uint32_t | |||||
.Fn Q_SIGNSHFT "QTYPE q" | |||||
.Ft QTYPE | |||||
.Fn Q_SSIGN "QTYPE q" "bool isneg" | |||||
.Ft ITYPE | |||||
.Fn Q_CRAWMASK "QTYPE q" | |||||
.Ft ITYPE | |||||
.Fn Q_SRAWMASK "QTYPE q" | |||||
.Ft ITYPE | |||||
.Fn Q_GCRAW "QTYPE q" | |||||
.Ft ITYPE | |||||
.Fn Q_GCVAL "QTYPE q" | |||||
.Ft QTYPE | |||||
.Fn Q_SCVAL "QTYPE q" "ITYPE cv" | |||||
.Sh DESCRIPTION | |||||
.Fn Q_SIGNSHFT | |||||
gets the bit position of | |||||
.Fa q Ap s | |||||
sign bit relative to bit zero. | |||||
.Pp | |||||
.Fn Q_SSIGN | |||||
sets the sign bit of | |||||
.Fa q | |||||
based on the boolean | |||||
.Fa isneg . | |||||
.Pp | |||||
.Fn Q_CRAWMASK | |||||
and | |||||
.Fn Q_SRAWMASK | |||||
return | |||||
.Fa q Ns -specific | |||||
bit masks for | |||||
.Fa q Ap s | |||||
control bits and sign bit respectively. | |||||
.Pp | |||||
.Fn Q_GCRAW | |||||
and | |||||
.Fn Q_GCVAL | |||||
get the raw masked control bits and value of | |||||
.Fa q Ap s | |||||
control bits respectively. | |||||
.Pp | |||||
.Fn Q_SCVAL | |||||
sets | |||||
.Fa q Ap s | |||||
control bits to the value | |||||
.Fa cv . | |||||
.Pp | |||||
All of those functions operate on | |||||
the following data types: | |||||
.Vt s8q_t , | |||||
.Vt u8q_t , | |||||
.Vt s16q_t , | |||||
.Vt u16q_t , | |||||
.Vt s32q_t , | |||||
.Vt u32q_t , | |||||
.Vt s64q_t , | |||||
and | |||||
.Vt u64q_t , | |||||
which are referred to generically as | |||||
.Fa QTYPE . | |||||
The | |||||
.Fa ITYPE | |||||
refers to the | |||||
.Xr stdint 7 | |||||
integer types. | |||||
.Pp | |||||
For more details, see | |||||
.Xr qmath 3 . | |||||
.Sh RETURN VALUES | |||||
.Fn Q_SIGNSHFT | |||||
returns the sign bit's position as an integer. | |||||
.Pp | |||||
.Fn Q_SSIGN | |||||
returns the value of | |||||
.Fa q | |||||
post change. | |||||
.Pp | |||||
.Fn Q_CRAWMASK , | |||||
.Fn Q_SRAWMASK , | |||||
.Fn Q_GCRAW | |||||
and | |||||
.Fn Q_GCVAL | |||||
return their respective values as integers of the same underlying ITYPE as | |||||
.Fa q . | |||||
.Pp | |||||
.Fn Q_SCVAL | |||||
returns the value of | |||||
.Fa q | |||||
post change. | |||||
.Sh SEE ALSO | |||||
.Xr errno 2 , | |||||
.Xr qmath 3 , | |||||
.Xr stdint 7 | |||||
.Sh HISTORY | |||||
The | |||||
.Xr qmath 3 | |||||
functions first appeared in | |||||
.Fx 13.0 . | |||||
.Sh AUTHORS | |||||
.An -nosplit | |||||
The | |||||
.Xr qmath 3 | |||||
functions and this manual page were written by | |||||
.An Lawrence Stewart Aq Mt lstewart@FreeBSD.org | |||||
and sponsored by Netflix, Inc. |