From: George Pee <georgepee@gmail.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
Russell King <linux@armlinux.org.uk>,
"Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>,
"Kirill A. Shutemov" <kirill.shtuemov@linux.intel.com>,
Austin Kim <austindh.kim@gmail.com>,
Ard Biesheuvel <ardb@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Report support for optional ARMv8.2 half-precision floating point extension
Date: Fri, 9 Sep 2022 09:57:39 -0500 [thread overview]
Message-ID: <CAKj0CMtkY_BSkAY3Lo5QbMDM1g0Wa9F8MsVuW0fyJiuPe3z4aA@mail.gmail.com> (raw)
In-Reply-To: <YxtIiBvAGs2vAl1P@arm.com>
The details are here. I originally thought it was a compiler bug
because it first showed up after a toolchain update.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106763
Since FP16 is an optional extension, wouldn't it be beneficial to a
user who compiled some userspace float16 code using gcc
-mcpu=cortex-a55 which ran on a cortex-a55 with FP16 extensions but
SIGILL'd on a cortex-a55 w/o FP16?
On Fri, Sep 9, 2022 at 9:07 AM Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Fri, Sep 09, 2022 at 08:34:26AM -0500, George Pee wrote:
> > Adding the hwcap was part of the diagnosis process-- I added it just
> > to make sure that the cpu in question supported the optional
> > extension.
> > It seems like it could be useful to be able to check for support in
> > /proc/cpuinfo.
>
> Ah, I wasn't aware that the feature doesn't work on arm32. I don't think
> it makes sense to expose a hwcap bit to user in this case.
>
> --
> Catalin
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-09-09 14:58 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 14:13 [PATCH] Report support for optional ARMv8.2 half-precision floating point extension george pee
2022-09-09 11:39 ` Catalin Marinas
2022-09-09 13:35 ` George Pee
2022-09-09 12:46 ` Robin Murphy
2022-09-09 13:34 ` George Pee
2022-09-09 14:07 ` Catalin Marinas
2022-09-09 14:57 ` George Pee [this message]
2022-09-09 15:05 ` Catalin Marinas
2022-09-12 13:05 ` Russell King (Oracle)
2022-09-12 18:09 ` George Pee
2022-09-09 14:17 ` Robin Murphy
2022-09-09 14:54 ` George Pee
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=CAKj0CMtkY_BSkAY3Lo5QbMDM1g0Wa9F8MsVuW0fyJiuPe3z4aA@mail.gmail.com \
--to=georgepee@gmail.com \
--cc=ardb@kernel.org \
--cc=austindh.kim@gmail.com \
--cc=catalin.marinas@arm.com \
--cc=kirill.shtuemov@linux.intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=rmk+kernel@armlinux.org.uk \
--cc=robin.murphy@arm.com \
--cc=rppt@kernel.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).