Differential D20116 Diff 59171 share/man/man3/Q_QADDQ.3

Changeset View

Standalone View

share/man/man3/Q_QADDQ.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_QADDQ 3
				.Os
				.Sh NAME
				.Nm Q_QADDQ ,
				.Nm Q_QDIVQ ,
				.Nm Q_QMULQ ,
				.Nm Q_QSUBQ ,
				.Nm Q_NORMPREC ,
				.Nm Q_QMAXQ ,
				.Nm Q_QMINQ ,
				.Nm Q_QCLONEQ ,
				.Nm Q_CPYVALQ
				.Nd fixed-point math functions which operate on two Q numbers
				.Sh SYNOPSIS
				.In sys/qmath.h
				.Ft int
				.Fn Q_QADDQ "QTYPE *a" "QTYPE b"
				.Ft int
				.Fn Q_QDIVQ "QTYPE *a" "QTYPE b"
				.Ft int
				.Fn Q_QMULQ "QTYPE *a" "QTYPE b"
				.Ft int
				.Fn Q_QSUBQ "QTYPE *a" "QTYPE b"
				.Ft int
				.Fn Q_NORMPREC "QTYPE a" "QTYPE b"
				.Ft QTYPE
				.Fn Q_QMAXQ "QTYPE a" "QTYPE b"
				.Ft QTYPE
				.Fn Q_QMINQ "QTYPE a" "QTYPE b"
				.Ft int
				.Fn Q_QCLONEQ "QTYPE *l" "QTYPE r"
				.Ft int
				.Fn Q_QCPYVALQ "QTYPE *l" "QTYPE r"
				.Sh DESCRIPTION
				The
				.Fn Q_QADDQ ,
				.Fn Q_QDIVQ ,
				.Fn Q_QMULQ ,
				and
				.Fn Q_QSUBQ
				functions add, divide, multiply or subtract
				.Fa b
				to/by/from
				.Fa a
				respectively, storing the result in
				.Fa a .
				.Pp
				The
				.Fn Q_NORMPREC
				function attempts to normalise the precision of
				.Fa a
				and
				.Fa b
				if they differ.
				The greater of the two precisions is preferred if possible, unless that would
				truncate integer component data for the other operand, in which case the highest
				precision that preserves the integer component of both
				.Fa a
				and
				.Fa b
				is selected.
				.Pp
				The
				.Fn Q_QMAXQ
				and
				.Fn Q_QMINQ
				functions return the larger or smaller of
				.Fa a
				and
				.Fa b
				respectively.
				.Pp
				The
				.Fn Q_QCLONEQ
				and
				.Fn Q_QCPYVALQ
				functions attempt to store identical or representational copies of
				.Fa r ,
				in
				.Fa l
				respectively.
				An identical Q number produced by cloning copies the control bits as well as the
				verbatim integer/fractional bits.
				A representational copy only copies the values of
				.Fa r Ap s
				integer and fractional bits, representing them in the bits available per
				.Fa l Ap s
				Q format.
				.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 .
				.Pp
				For more details, see
				.Xr qmath 3 .
				.Sh RETURN VALUES
				The
				.Fn Q_QADDQ ,
				.Fn Q_QDIVQ ,
				.Fn Q_QMULQ ,
				.Fn Q_QSUBQ
				.Fn Q_NORMPREC ,
				.Fn Q_QCLONEQ
				and
				.Fn Q_QCPYVALQ
				functions return 0 on success, or an errno on failure.
				.Er EINVAL
				is returned for divide-by-zero.
				.Er EOVERFLOW
				and
				.Er ERANGE
				are returned for overflow and underflow respectively.
				.Pp
				The
				.Fn Q_QMAXQ
				and
				.Fn Q_QMINQ
				functions return the numerically larger or smaller of their two inputs
				respectively.
				.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.