linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: David Laight <David.Laight@ACULAB.COM>
Cc: Nicolas Pitre <nico@fluxnic.net>, Antony Yu <swpenim@gmail.com>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	Nathan Chancellor <natechancellor@gmail.com>,
	'Ard Biesheuvel' <ardb@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [RESEND,PATCH] ARM: fix __div64_32() error when compiling with clang
Date: Mon, 30 Nov 2020 14:18:04 +0000	[thread overview]
Message-ID: <20201130141804.GV1551@shell.armlinux.org.uk> (raw)
In-Reply-To: <ca83a5acdf514169b2fde3ec12ea59fd@AcuMS.aculab.com>

On Mon, Nov 30, 2020 at 01:58:27PM +0000, David Laight wrote:
> > And actually, the same applies on BE, but the other way around. So we
> > should mark __xl as an output register as well, as __xl will assume
> > the right value depending on the endianness.
> 
> Why not use "+r" to indicate than an 'output' parameter is also
> used as an input.
> 
> Rather cleaner than specifying the same C variable as both
> input and output.

You have an incorrect understanding. "__n" is the input operand in r0.
"__rem" is the output operand in r0/r1.

No single C variable is used as both an input and an output.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2020-11-30 14:19 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-23  7:36 [RESEND,PATCH] ARM: fix __div64_32() error when compiling with clang Antony Yu
2020-11-23 18:16 ` Nathan Chancellor
     [not found]   ` <20201124074211.GA26157@penyung-VirtualBox>
2020-11-24 10:14     ` [RESEND, PATCH] " Antony Yu
2020-11-24 21:06       ` Nick Desaulniers
2020-11-30  8:20         ` [PATCH v2] " Antony Yu
2020-11-24 23:16 ` [RESEND,PATCH] " kernel test robot
2020-11-30 10:11 ` [RESEND, PATCH] " Ard Biesheuvel
2020-11-30 10:12   ` Ard Biesheuvel
2020-11-30 10:21     ` [RESEND,PATCH] " Russell King - ARM Linux admin
2020-11-30 10:40       ` [RESEND, PATCH] " Ard Biesheuvel
2020-11-30 13:58         ` [RESEND,PATCH] " David Laight
2020-11-30 14:18           ` Russell King - ARM Linux admin [this message]
2020-11-30 15:50     ` Nicolas Pitre
2020-11-30 17:18       ` [RESEND, PATCH] " Ard Biesheuvel
2020-11-30 17:52         ` [RESEND,PATCH] " Nicolas Pitre
2020-11-30 18:08           ` [RESEND, PATCH] " Ard Biesheuvel

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=20201130141804.GV1551@shell.armlinux.org.uk \
    --to=linux@armlinux.org.uk \
    --cc=David.Laight@ACULAB.COM \
    --cc=ardb@kernel.org \
    --cc=clang-built-linux@googlegroups.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=natechancellor@gmail.com \
    --cc=ndesaulniers@google.com \
    --cc=nico@fluxnic.net \
    --cc=swpenim@gmail.com \
    /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).