Re: -fno-tree-cselim not working?

[David Miller <davem at davemloft dot net>]

From: "Dave Korn" <dave.korn@artimi.com>
Date: Fri, 26 Oct 2007 17:35:44 +0100

> On 26 October 2007 17:28, Andrew Haley wrote:
> 
> > Richard Guenther writes:
> >  > >
> >  > > This is legal POSIX threads code: counter is not accessed when we do
> >  > > not hold the mutex.  According to POSIX we do not have to declare
> >  > > volatile memory that we only access when we hold a mutex.
> >  >
> >  > I hope we're not trying to support such w/o volatile counter.
> > 
> > I think we have to: not just for POSIX, but for the Linux kernel too.
> > 
> >  > Whatever POSIX says, this would pessimize generic code too much.
> > 
> > We don't have to do it for non-threaded code.
> 
>   I certainly won't object to any move to prohibit the
> read-conditional-add-write (and related) optimisation(s) when compiling with
> an option that explicitly specifies that we are compiling multi-threaded code.

What about signals?

Those are just another asynchronous context with similar issues.

Please don't point me at standards documents in your response,
that is not what truly matters here.