juniyonulFeb 20
Kenneth Hoste

If you're interested in RISC-V, this talk by @fclc from FOSDEM'26 is a must see...

RISC-V had 40 years of history to learn from: What it gets right, and what it gets hilariously wrong

https://fosdem.org/2026/schedule/event/X8TLY9-mistakes-in-riscv/

#riscv

FOSDEM 2026 - RISC-V had 40 years of history to learn from: What it gets right, and what it gets hilariously wrong

Feb 19 at 7:43amWeb
Show threadLynneFeb 20
@boegel @fclc One thing it didn't mention was the complete lack of support for timers. There used to be instructions to measure the current clock, but they were first made kernel-only, then completely removed due to "security" issues.
What good is having fast hardware if you cannot measure how fast given code actually is!?!
Show threadFCLCFeb 20

@lynne @boegel Yeah, lots more I would have covered given the time .

btw @lynne have you seen the Esperanto SIMD extensions? ET is out of business but I'm working on open sourcing part of their IP; it's mostly ment as a sort of AVX10.1 but 256 bit for Risc-V

Show threadLynneFeb 20
@fclc @boegel They're good. Fixed length is always a plus.
In multimedia, we pretty much always deal with fixed vector lengths, especially with video codecs. We've been able to awkwardly add some support for RISC-V, but it's still far from what we've been able to do for other architectures.
Show threadFCLCFeb 20

@lynne @boegel Yeah, I've got more to share soon, but I'm working on an evolution of those extensions as part of a community thing were I'll also be open sourcing the full spec and RTL for the unit, which itself will appear in real hardware.

RV politics aside, we've already upstreamed the ET-SIMD extensions into LLVM, and have real hardware that runs them for those interested

Show threadLynneFeb 20
@fclc @boegel Do you plan to propose them for standardization, or would they be mostly a vendor thing?
Show threadFCLCFeb 23

@lynne @boegel Intention is to propose for standardization!

Have had some early ping from other manufacturers that they're interested in using them

Show threadTrixFeb 20
@boegel @fclc I was disappointed I completely missed it IRL, learning about it like 2 hours after it happened, and was checking every few days if it was online yet 😃
Show threadKenneth HosteFeb 20

@trix @fclc You and me both!

I was well aware of the talk, but only got to the devroom 10min before the start, which made it totally hopeless to get in…

The recording is pretty good though!