maxdz8

Are we going to see shuffle in CL?

Discussion created by maxdz8 on Jan 31, 2015
Latest reply on Feb 10, 2015 by ekondis

I honestly forgot about it, but a couple of weeks ago realhet informed me shuffle is there for GCN at ISA level.

I could recall something about it and after a while I recalled a few pictures in GS-4106 The AMD GCN Architecture - A Crash Course, by Layla Mah.

SIMD_shuffle.png

I see broadcast in CL2 by work_group_broadcast and I can see why this is easier to specify than the rest but...

Full 4-lane xbar? Yes.

 

I would be happy to see this as extension so to bypass the lengthy scrutiny to core spec. Say an CL_AMD_GCN_SIMD_SHUFFLE, guaranteed to work only with work group size 64. It would be enough for me. Is there any hope?

Outcomes