[PATCH] Change default for --param allow-...-data-races to off

[Marc Glisse]

On Wed, 25 Jun 2014, Richard Biener wrote:

> On Wed, Jun 25, 2014 at 10:54 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>> On Wed, Jun 25, 2014 at 10:14:17AM +0200, Richard Biener wrote:
>>>> Perhaps not unsurprisingly, the patch is very similar.  Bootstrapped
>>>> and tested on x86_64-linux.  OK for trunk?
>>>
>>> Ok - please give the C++/atomics folks a chance to comment.
>>>
>>> This change of default behavior should also be documented in
>>> gcc-4.10/changes.html.
>>
>> Do we want to allow the store data races by default with -Ofast even in strict
>> conformance modes (-std=c++11, -std=c++14, -std=c11)?
>
> I think so.  -Ofast means -Ofast (same issue with fp contraction and other
> stuff -ffast-math enables that is not valid in strict conformance mode).

One thing I am missing is a -single-thread option that would allow races, 
remove atomics and thread locals, etc, without breaking conformance as 
long as no second thread is created. I hope that not too many libraries 
use threads internally in a way that would break this.

-- 
Marc Glisse