2fe8fb192f
There is important information about booting non-ack images in docs/UPDATING. ack/aout-format images can't be built any more, and booting clang/ELF-format ones is a little different. Updating to the new boot monitor is recommended. Changes in this commit: . drop boot monitor -> allowing dropping ack support . facility to copy ELF boot files to /boot so that old boot monitor can still boot fairly easily, see UPDATING . no more ack-format libraries -> single-case libraries . some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases . drop several ack toolchain commands, but not all support commands (e.g. aal is gone but acksize is not yet). . a few libc files moved to netbsd libc dir . new /bin/date as minix date used code in libc/ . test compile fix . harmonize includes . /usr/lib is no longer special: without ack, /usr/lib plays no kind of special bootstrapping role any more and bootstrapping is done exclusively through packages, so releases depend even less on the state of the machine making them now. . rename nbsd_lib* to lib* . reduce mtree
139 lines
4.1 KiB
Groff
139 lines
4.1 KiB
Groff
.\" $NetBSD: feclearexcept.3,v 1.2 2010/08/07 18:13:12 wiz Exp $
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.\" Copyright (c) 2004 David Schultz <das@FreeBSD.org>
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.Dd May 8, 2004
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.Dt FECLEAREXCEPT 3
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.Os
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.Sh NAME
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.Nm feclearexcept ,
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.Nm fegetexceptflag ,
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.Nm feraiseexcept ,
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.Nm fesetexceptflag ,
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.Nm fetestexcept
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.Nd floating-point exception flag manipulation
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.Sh LIBRARY
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.Lb libm
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.Sh SYNOPSIS
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.In fenv.h
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.Fd "#pragma STDC FENV_ACCESS ON"
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.Ft int
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.Fn feclearexcept "int excepts"
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.Ft int
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.Fn fegetexceptflag "fexcept_t *flagp" "int excepts"
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.Ft int
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.Fn feraiseexcept "int excepts"
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.Ft int
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.Fn fesetexceptflag "const fexcept_t *flagp" "int excepts"
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.Ft int
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.Fn fetestexcept "int excepts"
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.Sh DESCRIPTION
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The
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.Fn feclearexcept
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routine clears the floating-point exception flags specified by
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.Fa excepts ,
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whereas
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.Fn feraiseexcept
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raises the specified exceptions.
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Raising an exception causes the corresponding flag to be set,
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and a
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.Dv SIGFPE
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is delivered to the process if the exception is unmasked.
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.Pp
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The
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.Fn fetestexcept
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function determines which flags are currently set, of those specified by
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.Fa excepts .
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.Pp
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The
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.Fn fegetexceptflag
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function stores the state of the exception flags specified in
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.Fa excepts
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in the opaque object pointed to by
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.Fa flagp .
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Similarly,
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.Fn fesetexceptflag
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changes the specified exception flags to reflect the state stored in
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the object pointed to by
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.Fa flagp .
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Note that the flags restored with
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.Fn fesetexceptflag
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must be a (not necessarily proper) subset of the flags recorded by
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a prior call to
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.Fn fegetexceptflag .
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.Pp
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For all of these functions, the possible types of exceptions
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include those described in
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.Xr fenv 3 .
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Some architectures may define other types of floating-point exceptions.
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.Sh IMPLEMENTATION NOTES
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On some architectures, raising an overflow or underflow exception
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also causes an inexact exception to be raised.
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In these cases, the overflow or underflow will be raised first.
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.Pp
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The
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.Fn fegetexceptflag
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and
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.Fn fesetexceptflag
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routines are preferred to
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.Fn fetestexcept
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and
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.Fn feraiseexcept ,
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respectively, for saving and restoring exception flags.
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The latter do not re-raise exceptions and may preserve
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architecture-specific information such as addresses where
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exceptions occurred.
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.Sh RETURN VALUES
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The
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.Fn feclearexcept ,
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.Fn fegetexceptflag ,
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.Fn feraiseexcept ,
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and
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.Fn fesetexceptflag
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functions return 0 upon success, and non-zero otherwise.
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The
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.Fn fetestexcept
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function returns the bitwise OR of the values of the current exception
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flags that were requested.
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.Sh SEE ALSO
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.Xr sigaction 2 ,
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.Xr feholdexcept 3 ,
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.Xr fenv 3 ,
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.Xr feupdateenv 3 ,
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.Xr fpgetsticky 3
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.Sh STANDARDS
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The
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.Fn feclearexcept ,
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.Fn fegetexceptflag ,
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.Fn feraiseexcept ,
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.Fn fesetexceptflag ,
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and
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.Fn fetestexcept
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routines conform to
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.St -isoC-99 .
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.Sh HISTORY
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These functions first appeared in
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.Fx 5.3
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and
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.Nx 6.0 .
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