linux-toolchains.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Laight <David.Laight@ACULAB.COM>
To: David Laight <David.Laight@ACULAB.COM>,
	'Holger Lubitz' <holger.lubitz@t-online.de>,
	'Linus Torvalds' <torvalds@linux-foundation.org>,
	Guenter Roeck <linux@roeck-us.net>
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	"Jason A. Donenfeld" <Jason@zx2c4.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-kbuild@vger.kernel.org" <linux-kbuild@vger.kernel.org>,
	"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
	"linux-toolchains@vger.kernel.org"
	<linux-toolchains@vger.kernel.org>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"linux-m68k@lists.linux-m68k.org"
	<linux-m68k@lists.linux-m68k.org>
Subject: RE: [PATCH v2] kbuild: treat char as always unsigned
Date: Fri, 30 Dec 2022 13:13:55 +0000	[thread overview]
Message-ID: <a296bd41278d4bd4a4e9f0d31a540613@AcuMS.aculab.com> (raw)
In-Reply-To: <357cbd67260040e4bcf17d519aaafdcb@AcuMS.aculab.com>

....
> > int strcmp1(const char *cs, const char *ct)
> > {
> >         int res;
> >
> >         asm ("\n"
> >                 "1: move.b  (%0)+,%2\n"  /* get *cs */
> >                 "   jeq     2f\n"        /* end of first string? */
> >                 "   cmp.b   (%1)+,%2\n"  /* compare *ct */
> >                 "   jeq     1b\n"        /* if equal, continue */
> >                 "   jra     3f\n"        /* else skip to tail */
> >                 "2: cmp.b   (%1)+,%2\n"  /* compare one last byte */
> >                 "3: subx.l  %2, %2\n"    /* -1 if borrow, 0 if not */
> >                 "   jls     4f\n"        /* if set, z is from sub.b */
> 
> The subx will set Z unless C was set.
> So that doesn't seem right.

Clearly my brain was asleep earlier.
subx will clear Z not set it.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

  reply	other threads:[~2022-12-30 13:14 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-19 16:26 [PATCH] kbuild: treat char as always signed Jason A. Donenfeld
2022-10-19 16:54 ` Segher Boessenkool
2022-10-19 17:14   ` Linus Torvalds
2022-10-19 17:26     ` Linus Torvalds
2022-10-19 18:10       ` Nick Desaulniers
2022-10-19 18:35         ` Linus Torvalds
2022-10-19 19:23           ` Andy Shevchenko
2022-10-19 19:36             ` Linus Torvalds
2022-10-19 17:43     ` Segher Boessenkool
2022-10-19 18:11       ` Linus Torvalds
2022-10-19 18:20         ` Nick Desaulniers
2022-10-19 18:56           ` Linus Torvalds
2022-10-19 19:11             ` Kees Cook
2022-10-19 19:30               ` Linus Torvalds
2022-10-19 20:35                 ` Jason A. Donenfeld
2022-10-20  0:10                   ` Linus Torvalds
2022-10-20  3:11                     ` Jason A. Donenfeld
2022-10-19 20:15             ` Segher Boessenkool
2022-10-19 21:07         ` David Laight
2022-10-19 21:26           ` Segher Boessenkool
2022-10-20 10:41         ` Gabriel Paubert
2022-10-21 22:46           ` Linus Torvalds
2022-10-22  6:06             ` Gabriel Paubert
2022-10-22 18:16               ` Linus Torvalds
2022-10-23 20:23                 ` Gabriel Paubert
2022-10-25 23:00                   ` Kees Cook
2022-10-26  0:04                     ` Jason A. Donenfeld
2022-10-26 15:41                       ` Kees Cook
2022-10-19 19:54 ` Linus Torvalds
2022-10-19 20:23   ` Jason A. Donenfeld
2022-10-19 20:30     ` [PATCH v2] kbuild: treat char as always unsigned Jason A. Donenfeld
2022-10-19 23:56       ` Linus Torvalds
2022-10-20  0:02         ` Jason A. Donenfeld
2022-10-20  0:38           ` Linus Torvalds
2022-10-20  2:59             ` Jason A. Donenfeld
2022-10-20 18:41             ` Kees Cook
2022-10-21  1:01               ` Jason A. Donenfeld
2022-10-20 20:24         ` Segher Boessenkool
2022-10-24  9:24       ` Dan Carpenter
2022-10-24  9:30         ` Dan Carpenter
2022-10-24 16:33           ` Jason A. Donenfeld
2022-10-24 17:10             ` Linus Torvalds
2022-10-24 17:17               ` Jason A. Donenfeld
2022-10-25 19:22                 ` Kalle Valo
2022-10-25 10:16               ` David Laight
2022-10-24 15:17         ` Jason A. Donenfeld
2022-12-21 14:53       ` Guenter Roeck
2022-12-21 15:05         ` Geert Uytterhoeven
2022-12-21 15:23           ` Guenter Roeck
2022-12-21 15:29           ` Rasmus Villemoes
2022-12-21 15:56             ` Guenter Roeck
2022-12-21 17:06               ` Linus Torvalds
2022-12-21 17:19                 ` Guenter Roeck
2022-12-21 18:46                   ` Linus Torvalds
2022-12-21 19:08                     ` Linus Torvalds
2022-12-21 21:01                     ` Guenter Roeck
2022-12-22 13:05                     ` Geert Uytterhoeven
2022-12-22 10:41                 ` David Laight
     [not found]                   ` <f02e0ac7f2d805020a7ba66803aaff3e31b5eeff.camel@t-online.de>
2022-12-24  9:47                     ` Geert Uytterhoeven
2022-12-30 11:39                     ` David Laight
2022-12-30 13:13                       ` David Laight [this message]
2023-01-02  8:29                       ` Geert Uytterhoeven
2022-12-21 17:49               ` Andreas Schwab
2022-12-21 16:57             ` Geert Uytterhoeven
2022-10-19 20:58   ` [PATCH] kbuild: treat char as always signed David Laight
2022-10-26  0:10   ` make ctype ascii only? (was [PATCH] kbuild: treat char as always signed) Rasmus Villemoes
2022-10-26 18:10     ` Linus Torvalds
2022-10-27  7:59       ` Rasmus Villemoes
2022-10-27 18:28         ` Linus Torvalds
     [not found] ` <202210201618.8XhEGsLd-lkp@intel.com>
2022-10-20 16:33   ` [PATCH] kbuild: treat char as always signed Jason A. Donenfeld

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=a296bd41278d4bd4a4e9f0d31a540613@AcuMS.aculab.com \
    --to=david.laight@aculab.com \
    --cc=Jason@zx2c4.com \
    --cc=akpm@linux-foundation.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=geert@linux-m68k.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=holger.lubitz@t-online.de \
    --cc=keescook@chromium.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-m68k@lists.linux-m68k.org \
    --cc=linux-toolchains@vger.kernel.org \
    --cc=linux@roeck-us.net \
    --cc=masahiroy@kernel.org \
    --cc=rasmus.villemoes@prevas.dk \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).