[cfe-dev] Adding "simd" pragma to Clang

[Pekka Jääskeläinen]

On 02/14/2014 05:42 PM, Hal Finkel wrote:
> 1. Does our "llvm.mem.parallel_loop_access" metadata represent the implied
> semantics, which seem to cover "vector dependencies" but not loop-carried
> dependencies

IIRC the end result from the previous discussion was that
as it's not in general possible to know which are "compiler proven dependencies"
(and which only "assumed" due to, e.g., not having a smart enough AA),
we can might as well assume ivdep to have the "embarrassingly parallel
loop" semantics the llvm.mem.parallel_loop_access was intended originally
to denote. Seems Intel came to the same conclusion?

As ivdev semantics is so fuzzy, I'd discourage its usage in favor to the other
better specified pragmas, but might provide it just for the legacy
Intel-optimized codes.

BR,
-- 
--Pekka