On Thu, May 26, 2011 at 4:34 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Thu, May 26, 2011 at 04:29:50PM +0200, Richard Guenther wrote:
>> To make it a compiler memory barrier you have to "expand" the
>> builtin already in the frontend and present the middle-end with
>> __asm__ ("...." : : : "memory"). That will serve as a compiler
>> memory barrier also covering local non-address taken storage
>> (global and practically most of address-taken local storage
>> is covered by a builtin function call already).
>
> But then, what is the point of the builtin when
> __asm__ __volatile__ ("rep; nop" : : : "memory");
> does all of that already and has been supported for years...
Good question ;)
Richard.
