From: Jeff Law <law@redhat.com>
To: Bernd Edlinger <bernd.edlinger@hotmail.de>,
Richard Biener <richard.guenther@gmail.com>,
"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] Change default for --param allow-...-data-races to off
Date: Wed, 25 Jun 2014 21:14:00 -0000 [thread overview]
Message-ID: <53AB3BB7.7020603@redhat.com> (raw)
In-Reply-To: <20140624201933.GB32150@virgil.suse>
On 06/24/14 14:19, Martin Jambor wrote:
> On Mon, Jun 23, 2014 at 03:35:01PM +0200, Bernd Edlinger wrote:
>> Hi Martin,
>>
>>>>
>>>> Well actually, I am not sure if we ever wanted to have a race condition here.
>>>> Have you seen any impact of --param allow-store-data-races on any benchmark?
>>>
>>> It's trivially to write one. The only pass that checks the param is
>>> tree loop invariant motion and it does that when it applies store-motion.
>>> Register pressure increase is increased by a factor of two.
>>>
>>> So I'd agree that we might want to disable this again for -Ofast.
>>>
>>> As nothing tests for the PACKED variants nor for the LOAD variant
>>> I'd rather remove those. Claiming we don't create races for those
>>> when you disable it via the param is simply not true.
>>>
>>> Thanks,
>>> Richard.
>>>
>>
>> OK, please go ahead with your patch.
>
> Perhaps not unsurprisingly, the patch is very similar. Bootstrapped
> and tested on x86_64-linux. OK for trunk?
>
> Thanks,
>
> Martin
>
>
> 2014-06-24 Martin Jambor <mjambor@suse.cz>
>
> * params.def (PARAM_ALLOW_LOAD_DATA_RACES)
> (PARAM_ALLOW_PACKED_LOAD_DATA_RACES)
> (PARAM_ALLOW_PACKED_STORE_DATA_RACES): Removed.
> (PARAM_ALLOW_STORE_DATA_RACES): Set default to zero.
> * opts.c (default_options_optimization): Set
> PARAM_ALLOW_STORE_DATA_RACES to one at -Ofast.
> * doc/invoke.texi (allow-load-data-races)
> (allow-packed-load-data-races, allow-packed-store-data-races):
> Removed.
> (allow-store-data-races): Document the new default.
>
> testsuite/
> * g++.dg/simulate-thread/bitfields-2.C: Remove allow-load-data-races
> parameter.
> * g++.dg/simulate-thread/bitfields.C: Likewise.
> * gcc.dg/simulate-thread/strict-align-global.c: Remove
> allow-packed-store-data-races parameter.
> * gcc.dg/simulate-thread/subfields.c: Likewise.
> * gcc.dg/tree-ssa/20050314-1.c: Set parameter allow-store-data-races
> to one.
Don't we want to deprecate, not remove the dead options?
Jeff
next prev parent reply other threads:[~2014-06-25 21:14 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-19 16:18 Bernd Edlinger
2014-06-20 11:44 ` Martin Jambor
2014-06-23 8:03 ` Bernd Edlinger
2014-06-23 8:50 ` Richard Biener
2014-06-23 13:35 ` Bernd Edlinger
2014-06-24 20:19 ` Martin Jambor
2014-06-25 8:14 ` Richard Biener
2014-06-25 8:54 ` Jakub Jelinek
2014-06-25 8:56 ` Richard Biener
2014-06-25 9:48 ` Marc Glisse
2014-06-25 21:14 ` Jeff Law [this message]
2014-06-25 22:03 ` Martin Jambor
2014-06-26 6:43 ` Richard Biener
2014-06-26 7:53 ` Bernd Edlinger
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=53AB3BB7.7020603@redhat.com \
--to=law@redhat.com \
--cc=bernd.edlinger@hotmail.de \
--cc=gcc-patches@gcc.gnu.org \
--cc=richard.guenther@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 read-only IMAP folder(s) and NNTP newsgroup(s).