[PATCH v1 1/1] riscv: Add RVV memset via multiarch/IFUNC

[Jeff Law]

On 10/30/25 5:25 AM, Florian Weimer wrote:
> * Palmer Dabbelt:
> 
>> On Wed, 29 Oct 2025 19:01:22 PDT (-0700), bergner@tenstorrent.com wrote:
>>> On 10/29/25 6:36 PM, Palmer Dabbelt wrote:
>>>> You're talking glibc-hwcaps though, right?  Jeff is saying AT_HWCAP,
>>>> which is busted on RISC-V (we allocated a bunch of bits early and then
>>>> vendors did whatever they wanted, V got specifically tied up with the
>>>> V-0.7.1 stuff).
>>>
>>> Yes, I was talking about glibc-hwcaps, not AT_HWCAP.
>>
>> Ya, so I think last time we talked about glibc-hwcaps the basic takeaway
>> was that we just didn't know what HW was going to look like, so adding a
>> glibc-hwcap would be premature.
> 
> I think it depends on how serious the ecosystem is about killing off
> the base ISA (at least in the glibc context).  If we don't expect
> distributions to switch to RVA23 in the next year or two, maybe adding
> an RVA23 subdirectory still makes sense.  Of course, if RVA23 gets
> adopted by distributions faster than glibc 2.43, that's unnecessary.
Unfortunately Debian seems to have landed on RVA20.  and as you know, 
once a distro does that, getting it moved to something more modern is a 
major effort ;(  I understand how that get to that decision, it's just 
going to make it tougher to move the baseline forward in the future...

Meaning I suspect we ultimately end up with a glibc-hwcap for rva23.

Jeff