Re: [PATCH v3 0/6] RISC-V: Support XTheadVector extension

[Jeff Law <jeffreyalaw@gmail.com>]

On 12/20/23 20:30, juzhe.zhong@rivai.ai wrote:
> OK.  Sounds reasonable.
> 
> But from my side, I used to commit patches after full coverage testing.
Understood.  And it's appreciated -- the code you're doing hits a wide 
variety of configurations, so the wider testing is probably applicable.

Ideally the thead vector bits need reasonable testing to make sure they 
don't totally break the standard RVV support.  So for something like the 
final scheme to add the "th." prefix I'd expect they can get away with 
just rv64gcv.  WHile there is a chance that'll miss something, the odds 
are pretty low that a bug will be uncovered for each additional 
configuration tested beyond the first.

In contrast if they needed to make a structural changes that are more 
than adding a path for thead's vector unit, then we might reasonably ask 
for a deeper test of that specific patch (perhaps even suggesting the 
configurations most likely affected and thus which need to be tested).

The key being we want to use time wisely and testing dozens of multilibs 
for each change isn't really reasonable.

It's always a delicate balance to articulate the right level of testing 
because the "right" level can vary based on each engineer's risk 
assessment of a particular change.

Jeff