Newsgroups: fj.lang.c
Path: galaxy.trc.rwcp.or.jp!coconuts.jaist!wnoc-tyo-news!etlnews.etl.go.jp!news.trc!nf2.iij.ad.jp!nr0.iij.ad.jp!news.iij.ad.jp!rim.or.jp!Q.T.Honey!netaidnews!news6-tokyonet!tokyonet.ad.jp!feed-tokyonet!astecgw!news
From: Hisao Aoyama <aoyama@astec.co.jp>
Subject: Re: Q:volatile pointer
X-Nntp-Posting-Host: kamui.astec.co.jp
Content-Type: text/plain; charset=ISO-2022-JP
Message-ID: <v4zpk9otvs.fsf@astec.co.jp>
Lines: 48
Sender: aoyama@kamui
Organization: ASTEC, Inc. Tokyo, Japan
X-Newsreader: Gnus v5.3/Emacs 19.34
References: <34D09B5C.5EFA@mxp.meshnet.or.jp>
	<HOSHI.98Feb2134253@sras49.sra.co.jp>
Mime-Version: 1.0 (generated by tm-edit 7.105)
Date: Tue, 3 Feb 1998 10:38:47 GMT
Xref: galaxy.trc.rwcp.or.jp fj.lang.c:5429
X-originally-archived-at: http://galaxy.rwcp.or.jp/text/cgi-bin/newsarticle2?ng=fj.lang.c&nb=5429&hd=a
X-reformat-date: Mon, 18 Oct 2004 15:18:22 +0900
X-reformat-comment: Tabs were expanded into 4 column tabstops by the Galaxy's archiver. See http://katsu.watanabe.name/ancientfj/galaxy-format.html for more info.

hoshi@sra.co.jp (Hoshi Takanori) writes:

> $B$H$3$m$G!"JX>h$7$F<ALd(B ($B$3$l$,K\Bj(B) $B$G$9$,!"(Bm68 $BMQ$N(B gcc (2.4.5
> $B$H(B 2.7.2.2 $B$G3NG'$7$^$7$?!#(B) $B$G!"(B
> 
>     volatile char *p;
> 
>     p |= 1;
> 
> $B$H$9$k$H!"(B

$B$-$C$H(B

    *p |= 1;

$B$N4V0c$$$G$9$M!%(B

> -O $B$N;XDj$K$h$i$:!"(B
> 
>     move.b (a0),d0
>     or.b #1,d0
>     move.b d0,(a0)
> 
> $B$H$$$&4VH4$1$J%3!<%I$rEG$$$F$/$l$^$9!#4|BT$9$k%3!<%I(B
> 
>     or.b #1,(a0)
> 
> $B$rEG$$$F$/$l$k$h$&$K$9$kJ}K!$O!"(Basm $B0J30$K$O$J$$$N$G$7$g$&$+!)(B

$B$=$l$O(B gcc $B$N%=!<%9$K?R$M$F$b$i$C$?J}$,3N<B$G$9$,!$(Basm $B$N>l9g$G$b(B

        volatile char *p;

    #if defined(__GNUC__) && defined(__mc68000__)
        asm volatile("orb #1,%0"  : "=m" (*p));
    #else
        *p |= 1;
    #endif

$B$N$h$&$K(B 1 $B9T$@$1=q$$$FJQ?t$H%l%8%9%?$NBP1~$,$H$l$k$O$:$J$N$G!$$=(B
$B$s$J$KBgJQ$G$O$J$$$G$7$g$&!%(B

----
Hisao Aoyama $B@D;3(B $B>0IW(B
ASTEC, Inc.  $B!J3t!K%"%9%F%C%/(B
aoyama@astec.co.jp


