[libre-riscv-dev] daily kan-ban update 08jun2020

[Cole Poirier]

> On Jun 8, 2020, at 3:13 PM, Luke Kenneth Casson Leighton <lkcl at lkcl.net> wrote:

> yyeah.  last time i explained it to someone (in detail) it was to
> Alain.  it took six hours.
> 
> the summary: rather than have dozens of instructions ADD x1, x10 ADD
> x2, x11 ADD x3, x12, instead you deploy SimpleV - with *one*
> instruction - telling it (by setting VL) exactly how many registers,
> in sequence, you would like that *ONE* instruction to push into the
> instruction queue.
> 
> that's basically all there is to it.  it should be pretty obvious
> therefore that it is effectively a very simple version of an
> instruction "compression algorithm".
> 
> in effect, Simple-V is a hardware-level for-loop.  if you have heard
> of Zero-Overhead Loops, it is a bit like that.  except, whilst ZOHLs
> loop around a *group* of instructions, Simple-V gives the option to
> apply the for-loop to *ANY* instruction, and does so *on* that
> instruction *before* moving on to the next one.
> 
> it's like a Sub- Program Counter, in effect

Aha that makes sense! I’ll integrate this into the rest of the insights from the list earlier today.

> 
>> Can I ask you to see if you're able to answer some of these questions
>> today, if your illness permits?
> 
> it's fine, now: i took... i won't go into the medical details, there's
> a procedure i follow which clears out toxins and it was effective.
> also, a drink made from large quantities of ginger root, cardamons,
> black pepper and chilis, caused me to cough and splutter and generally
> hawk and spit profusely (as might be expected), and surpriise! i'm
> feeling much better.
> 
> l.

I’m glad to hear you’re feeling better! However you’ve figured out how to make it happen. Thanks Luke, I’ll hopefully have something for you in about an hour.

Cole