David Edelsohn wrote:
On Wed, Sep 3, 2008 at 3:06 AM, Anton Blanchard <[EMAIL PROTECTED]> wrote:
Why does the GCC alpha port emit a memory barrier at the beginning of the
test_and_set sync builtin sequence, which seems to be more than
the required `acquire' semantics?
Um, that's a good question
On Wed, Sep 3, 2008 at 3:06 AM, Anton Blanchard <[EMAIL PROTECTED]> wrote:
> unlock looks good, but lock has both release and acquire barriers. Even
> worse, the release barrier is a heavyweight sync which is very slow.
> Looking at the gcc documentation, sync_lock_test_and_set only needs an
> aqui
Hi,
I was debugging some performance issues with an application that uses
the gcc builtin lock functions on powerpc. A simple test case:
long lock_try(long *value)
{
return __sync_lock_test_and_set(value, 1);
}
long unlock(long *value)
{
__sync_lock_release(value);
}
0010 :
