public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "amonakov at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/111768] X86: -march=native does not support alder lake big.little cache infor correctly
Date: Thu, 12 Oct 2023 06:59:55 +0000 [thread overview]
Message-ID: <bug-111768-4-BlSwjDvWEf@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-111768-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111768
Alexander Monakov <amonakov at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |amonakov at gcc dot gnu.org
--- Comment #7 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
I'm afraid hybrid CPUs with varying ISA feature sets are not practical for the
current ecosystem: you wouldn't be able to reschedule from a higher- to
lower-capable core. Not to mention scenarios like Mesa on-disk llvmpipe shader
cache.
"Always" probing all cores is a not a good idea (the compiler would have to
manually reschedule itself to all cores, of which there could be hundreds).
Plus, portable API for such probing across available cores does not exist
afaik.
I think releasing an x86 hybrid CPU with varying capabilities across cores
would require substantial preparatory work in the kernel and likely in the
userland as well, so probably best to leave it until the time comes and
specifics of what can differ are known.
next prev parent reply other threads:[~2023-10-12 6:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-11 10:11 [Bug bootstrap/111768] New: Bootstrap failure with -march=native on Intel Alder Lake CPUs because of differing cache sizes sjames at gcc dot gnu.org
2023-10-11 10:11 ` [Bug bootstrap/111768] " sjames at gcc dot gnu.org
2023-10-11 13:02 ` [Bug target/111768] X86: -march=native does not support alder lake big.little cache infor correctly pinskia at gcc dot gnu.org
2023-10-11 13:26 ` rguenth at gcc dot gnu.org
2023-10-11 13:55 ` crazylht at gmail dot com
2023-10-11 14:13 ` amonakov at gcc dot gnu.org
2023-10-12 6:32 ` arsen at gcc dot gnu.org
2023-10-12 6:59 ` amonakov at gcc dot gnu.org [this message]
2023-10-12 9:45 ` arsen at gcc dot gnu.org
2023-10-12 9:55 ` amonakov at gcc dot gnu.org
2023-10-12 10:49 ` crazylht at gmail dot com
2023-10-12 11:25 ` amonakov at gcc dot gnu.org
2023-10-12 11:32 ` rguenth at gcc dot gnu.org
2023-10-12 13:23 ` stormbyte at gmail dot com
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=bug-111768-4-BlSwjDvWEf@http.gcc.gnu.org/bugzilla/ \
--to=gcc-bugzilla@gcc.gnu.org \
--cc=gcc-bugs@gcc.gnu.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 read-only IMAP folder(s) and NNTP newsgroup(s).