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SubjectRe: [tip:locking/core] locking/atomics: Simplify the op definitions in atomic.h some more
On Tue, May 15, 2018 at 07:10:21PM +0200, Peter Zijlstra wrote:
> On Tue, May 15, 2018 at 04:43:33PM +0100, Mark Rutland wrote:
> > I *think* the table can encode enough info to generate atomic-long.h,
> > atomic-instrumented.h, and the atomic.h ordering fallbacks. I'll need to
> > flesh out the table and check that we don't end up clashing with
> > some of the regular fallbacks.
>
> Yes, details details ;-)
>
> > # name meta args...
> > #
> > # Where meta contains a string of:
> > # * B - bool: returns bool, fully ordered
> > # * V - void: returns void, fully ordered
>
> void retuns are relaxed

How about:

V - void: returns void, no ordering variants (implicitly relaxed)

> > # * I - int: returns base type, all orderings
> > # * R - return: returns base type, all orderings
> > # * F - fetch: returns base type, all orderings
> > # * T - try: returns bool, all orderings
>
> Little more verbose than mine, I think we can get there with X and XB
> instead of I and T, but whatever :-)

Mhmm. I found it easier to do switch-like things this way, but it works
regardless.

> > # Where args contains list of type[:name], where type is:
> > # * v - pointer to atomic base type (atomic or atomic64)
> > # * i - base type (int or long)
> > # * I - pointer to base type (int or long)
> > #
> > add VRF i v
> > sub VRF i v
> > inc VRF v
> > dec VRF v
> > or VF i v
> > and VF i v
> > andnot VF i v
> > xor VF i v
> > xchg I v i
> > cmpxchg I v i:old i:new
> > try_cmpxchg T v I:old i:new
> > add_and_test B i v
> > sub_and_test B i v
> > dec_and_test B v
> > inc_and_test B v
>
> Cute, that [:name].

:D

Thanks,
Mark.

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