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Add __insn_barrier(3). XXX: Someone more knowledgeable may want to check this.

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jruoho 2010-12-17 07:10:37 +00:00
parent 1ee8ff33ba
commit 52b33dcfd8
4 changed files with 77 additions and 8 deletions
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5
distrib/sets/lists/comp/mi
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@ -1,4 +1,4 @@
# $NetBSD: mi,v 1.1551 2010/12/16 23:01:56 joerg Exp $
# $NetBSD: mi,v 1.1552 2010/12/17 07:10:37 jruoho Exp $
#
# Note: don't delete entries from here - mark them as "obsolete" instead.
#
@ -4910,6 +4910,7 @@
./usr/share/man/cat3/__builtin_object_size.0 comp-c-catman .cat
./usr/share/man/cat3/__constfunc.0 comp-c-catman .cat
./usr/share/man/cat3/__dead.0 comp-c-catman .cat
./usr/share/man/cat3/__insn_barrier.0 comp-c-catman .cat
./usr/share/man/cat3/__noinline.0 comp-c-catman .cat
./usr/share/man/cat3/__packed.0 comp-c-catman .cat
./usr/share/man/cat3/__pure.0 comp-c-catman .cat
@ -10994,6 +10995,7 @@
./usr/share/man/html3/__builtin_object_size.html comp-c-htmlman html
./usr/share/man/html3/__constfunc.html comp-c-htmlman html
./usr/share/man/html3/__dead.html comp-c-htmlman html
./usr/share/man/html3/__insn_barrier.html comp-c-htmlman html
./usr/share/man/html3/__noinline.html comp-c-htmlman html
./usr/share/man/html3/__packed.html comp-c-htmlman html
./usr/share/man/html3/__pure.html comp-c-htmlman html
@ -16878,6 +16880,7 @@
./usr/share/man/man3/__builtin_object_size.3 comp-c-man .man
./usr/share/man/man3/__constfunc.3 comp-c-man .man
./usr/share/man/man3/__dead.3 comp-c-man .man
./usr/share/man/man3/__insn_barrier.3 comp-c-man .man
./usr/share/man/man3/__noinline.3 comp-c-man .man
./usr/share/man/man3/__packed.3 comp-c-man .man
./usr/share/man/man3/__pure.3 comp-c-man .man

5
share/man/man3/Makefile
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@ -1,8 +1,9 @@
# $NetBSD: Makefile,v 1.61 2010/12/16 17:47:54 jruoho Exp $
# $NetBSD: Makefile,v 1.62 2010/12/17 07:10:38 jruoho Exp $
# @(#)Makefile 8.2 (Berkeley) 12/13/93
MAN= _DIAGASSERT.3 __CONCAT.3 __UNCONST.3 CMSG_DATA.3 \
__arraycount.3 assert.3 attribute.3 bits.3 bitstring.3 \
__arraycount.3 __insn_barrier.3 \
assert.3 attribute.3 bits.3 bitstring.3 \
cdefs.3 dirent.3 dlfcn.3 dl_iterate_phdr.3 end.3 \
fast_divide32.3 ffs32.3 gcq.3 \
ilog2.3 intro.3 inttypes.3 iso646.3 \

64
share/man/man3/__insn_barrier.3 Normal file
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@ -0,0 +1,64 @@
.\" $NetBSD: __insn_barrier.3,v 1.1 2010/12/17 07:10:38 jruoho Exp $
.\"
.\" Copyright (c) 2010 Jukka Ruohonen <jruohonen@iki.fi>
.\" 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.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.Dd December 17, 2010
.Dt __INSN_BARRIER 3
.Os
.Sh NAME
.Nm __insn_barrier
.Nd compiler reorder barrier
.Sh SYNOPSIS
.In sys/cdefs.h
.Ft void
.Fn __insn_barrier
.Sh DESCRIPTION
The
.Fn __insn_barrier
macro prevents
.Tn GCC
from moving code across the barrier.
In other words, the compiler is not allowed to reorder read and write
commands below the barrier with the code preceding the barrier.
Like with the
.Em volatile
type qualifier,
.Fn __insn_barrier
may be necessary in some corner cases to prevent the compiler
from misoptimizing.
.Sh SEE ALSO
.Xr gcc 1 ,
.Xr cdefs 3
.Rs
.%A Paul E. McKenney
.%T Memory Barriers: a Hardware View for Software Hackers
.%D June 7, 2010
.%U http://www.rdrop.com/users/paulmck/scalability/paper/whymb.2010.06.07c.pdf
.Re
.Sh HISTORY
The
.Fn __insn_barrier
macro first appeared in
.Nx 2.0 .

11
share/man/man3/cdefs.3
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@ -1,4 +1,4 @@
.\" $NetBSD: cdefs.3,v 1.1 2010/12/16 10:19:14 jruoho Exp $
.\" $NetBSD: cdefs.3,v 1.2 2010/12/17 07:10:38 jruoho Exp $
.\"
.\" Copyright (c) 2010 The NetBSD Foundation, Inc.
.\" All rights reserved.
@ -27,7 +27,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd December 16, 2010
.Dd December 17, 2010
.Dt CDEFS 3
.Os
.Sh NAME
@ -54,10 +54,11 @@ type qualifier from
.Tn C99 .
.It
Macros and definitions specific to compilers, preprocessors, and linkers; see
.Xr attribute 3 ,
.Xr __CONCAT 3 ,
.Xr __UNCONST 3 ,
.Xr __insn_barrier 3 ,
and
.Xr __UNCONST 3 .
.Xr attribute 3 .
.It
Utility macros provided for convenience; see
.Xr __arraycount 3
@ -87,7 +88,7 @@ included as the first thing right after any possible copyright texts;
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: cdefs.3,v 1.1 2010/12/16 10:19:14 jruoho Exp $");
__RCSID("$NetBSD: cdefs.3,v 1.2 2010/12/17 07:10:38 jruoho Exp $");
.Ed
.Pp
It is possible to identify the