Comment by camel-cdr
2 years ago
T-Head also has their own matmul extensions, but t-head, SiFive, Andes, Rivos, IMB, ... have all people working on the risc-v integrated matrix extension spec.
The vendors presented their own matmul extensions, but none of them solve all problems that the integrated matrix extension should solve. Most importantly binary compatibility across vector lengths. The last to meeting presented alternatives that would satisfy that requirement. It will however take some time to decide on and experiment with the best design.
I agree that this can turn out messy, so far I haven't seen anyone, outside of vendor libraries, use the t-head or SiFive matmul extensions in open source code.
Ventanas ternary op and similar will hopefuly consolidate on the cmov extension.
At some point we will get a matmul extension which fit- a good set of compromises/use cases.
(there are still people thinking there will be no tradeoff).
cmov extension? Like on x86?
I agree the situation changes if there is a single new spec, this is why I wrote "at the moment". Do you have any insight on when it's finished/ widely available? I'd guess two years?