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* New MI man page for fp{set,get}{round,sticky,mask}(3).
* Implement fpgetsticky() for alpha.
* Direct fpsetsticky() and fp{get,set}mask() into alpha kernel via sysarch(2).
* Define new sysarch(2) stub for above and install and distribute sysarch.h
for alpha.  (The fpcr IS user mode r/w, but for reasons beyond the scope
of a commit message kernel calls are needed.) And much kernel Magick is
required before these do anything, but this way programs compiled under
1.4 will DTRT on future snapshots and releases.

.\"	$NetBSD: fpgetmask.3,v 1.1 1999/04/30 00:58:31 ross Exp $
.\"
.\" Copyright (c) 1999 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Ross Harvey.
.\"
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.\" modification, are permitted provided that the following conditions
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.\"    must display the following acknowledgement:
.\"        This product includes software developed by the NetBSD
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.Dd April 29, 1999
.Dt FPGETMASK 3
.Os
.Sh NAME
.Nm fpgetmask ,
.Nm fpgetround ,
.Nm fpgetsticky ,
.Nm fpsetmask ,
.Nm fpsetround ,
.Nm fpsetsticky
.Nd IEEE FP mode control
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.Fd #include <ieeefp.h>
.Ft fp_except
.Fn fpgetmask void
.Ft fp_rnd
.Fn fpgetround void
.Ft fp_except
.Fn fpgetsticky void
.Ft fp_except
.Fn fpsetmask fp_except\ mask
.Ft fp_rnd
.Fn fpsetround fp_rnd\ rnd_dir
.Ft fp_except
.Fn fpsetsticky fp_except\ sticky
.Sh DESCRIPTION
A rounding mode is one of
.Dv FP_RZ , FP_RM , FP_RN ,
or
.Dv FP_RP ,
for rounding towards zero, rounding
.Pq Em Minus infinity
down, rounding to
.Em nearest ,
and rounding 
.Pq Em Plus infinity
up.
The default mode is
.Dv FP_RN .
.Pp
An
.Ft fp_except
value is a bitmask specifying an exception type and containing any of
the values listed below.
.Bl -column -offset indent FP_X_UFLxx
.It Dv FP_X_INV Ta Invalid\ Operation
.It Dv FP_X_DZ Ta Division\ by\ zero
.It Dv FP_X_OFL Ta Overflow
.It Dv FP_X_UFL Ta Underflow
.It Dv FP_X_IMP Ta Imprecision (inexact)
.It Dv FP_X_IOV Ta Integer\ Overflow
.El
.Pp
.Pp
The
.Fn fpsetmask
function will cause future operations with the specified result status to
raise the
.Dv SIGFPE
exception.
The
.Fn fpsetround
function will cause future operations to use the specified dynamic mode.
.Bl -tag -width Note:x
.It Em Note:
On some architectures, instructions can optionally specify static
rounding modes and exception enables that will supersede the specified
dynamic mode. On other architectures, these features may not be fully
supported.
.El
.Pp
The
.Fn fpsetsticky
function will set or clear the specified exception history bits.
.Sh RETURN VALUES
The
.Fn fpgetround
and
.Fn fpsetround
functions return the
.Pq previous
rounding mode.
The
.Fn fpgetmask ,
.Fn fpsetmask ,
.Fn fpgetsticky ,
and
.Fn fpsetsticky
functions return the
.Pq previous
exception mask and exception history bits.
.Sh SEE ALSO
.Xr sigaction 2