[ltt-dev] [PATCH] arm: remove useless declarations

Paul E. McKenney paulmck at linux.vnet.ibm.com
Thu Jun 9 12:43:08 EDT 2011

On Thu, Jun 09, 2011 at 04:25:44PM +0200, Paolo Bonzini wrote:
> On 06/09/2011 04:21 PM, Mathieu Desnoyers wrote:
> >I'd first like to understand why Paul chose to override the generic
> >versions of these macros. There is a change in what you map to:
> >
> >__sync_val_compare_and_swap ->  __sync_val_compare_and_swap_1/2/4/8
> >
> >__sync_add_and_fetch ->  __sync_add_and_fetch_1/2/4/8
> >
> >Were there any problems with the _N variants on some ARM compilers ?
> The non-"_N" variants do not exist outside the back-end (they are
> mapped to the "_N" variants by target-independent parts of the
> compiler), but I agree that Paul's ack is good to have.

In some of the older versions of ARM Linux and toolchain, many of which
are unfortunately still in heavy use, the __sync_synchronize() primitive
was broken (as in was a no-op), but from what I can see the others worked
just fine.

							Thanx, Paul

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