Comment by luyu_wu
2 years ago
Unfortunately, RISCV is really a mess right now, the Vector extensions are horrible. Amusingly, LoongArch has better Linux support than RISCV right now too... Would've definetly been nice to see them adopt RISCV though. ISAs are fragmented enough as is.
> the Vector extensions are horrible
How so?
They're horribly fragmented (there's many ISA extensions that accomplish the same thing from different companies), and thus a headache to deal with for any compiler (which is why the compiler support sucks).
There is one standard vector extension, and one company that released two chips with a non standard pre ratification version of the extension.
It was released almost two years before the first rvv 1.0 hardware became available at the end of last year. Without out it, we wouldn't have had any hardware at all.
rvv 1.0 has quite good upstream compiler support already, and before that the t-head had custom compilers that supported their rvv 0.7.1 version of the vector extension.
Now upstream gcc supports it as an alternative codegen target as well, so you can write rvv 1.0 vector instrinsics and compile those to the thead rvv 0.7.1 implementation.
I'm not aware of any company that plans to release a non rvv 1.0 rvv implementation.
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