Re: src/winsup/w32api ChangeLog include/winnt.h

On Thu, Aug 2, 2012 at 4:40 AM, Václav Zeman wrote:
> On 1 August 2012 21:17,  <earnie <at> ...> wrote:
>> CVSROOT:        /cvs/src
>> Module name:    src
>> Changes by:     earnie <at> ...   2012-08-01 19:17:37
>>
>> Modified files:
>>         winsup/w32api  : ChangeLog
>>         winsup/w32api/include: winnt.h
>>
>> Log message:
>>         * include/winnt.h (MemoryBarrier): Add definition.
>>
>> Patches:
>> http://sourceware.org/cgi-bin/cvsweb.cgi/src/winsup/w32api/ChangeLog.diff?cvsroot=src&r1=1.1121&r2=1.1122
>> http://sourceware.org/cgi-bin/cvsweb.cgi/src/winsup/w32api/include/winnt.h.diff?cvsroot=src&r1=1.139&r2=1.140
>>
>
> +# else
> +   FORCEINLINE VOID MemoryBarrier (VOID) {
> +       LONG Barrier = 0;
> +       __asm__ __volatile__("xchgl %%eax,%0 "
> +         :"=r" (Barrier));
> +   }
>
> Since this is for GCC anyway, why not using __sync_synchronize() in
> the body of the function instead?

I found the code elsewhere and rather trust the author of that bit.
However, if you can provide test programs showing the differences of