HIP-CPU icon indicating copy to clipboard operation
HIP-CPU copied to clipboard

Missing some warp cross lane functions

Open ueqri opened this issue 2 years ago • 1 comments

According to HIP programming guides, Warp Cross Lane Functions are well supported in HIP. But I couldn't build the HIP code with some of these wrap functions e.g. int __all(int predicate) and int __any(int predicate) using HIP-CPU library.

Since those APIs are widely used in warp-level programing, I was wondering if there are some plans for these functions, __all and __any (__ballot is already implemented in HIP-CPU).

ueqri avatar Jul 11 '21 17:07 ueqri

Thank you for filing this @ueqri . I will add them, but please note that there's a caveat with Cross Lane Functions (it's one of the divergence points between CPU and GPU), in that on CPU these'll carry barrier semantics (as if calling __syncthreads). I think that @MathiasMagnus ran into it, so he might have something to add.

AlexVlx avatar Jun 18 '22 00:06 AlexVlx