[Libre-soc-dev] VSX pseudo-code Extraction

Luke Kenneth Casson Leighton lkcl at lkcl.net
Fri Feb 19 21:18:31 GMT 2021


https://bugs.libre-soc.org/show_bug.cgi?id=602#c1

i'm going through the pages now, marking out the page numbers.  it is
just... awful.  it's excruciatingly painful to think and realise just how
much work (how much money) went into this paradigm, when SV "contexts"
covers literally 100% of them, based on a few generally-abstracted
principles.

example:

compare all words greater
compare all words lessthan
compare all worss notequal
compare all bytes ...
...
...

all of that's covered and then some with a vectorised scalar cmp operation
(or any arithmetic operation when vectorised also produces a vector of CRs)
followed by a mapreduce on CR ops.  pick one.  CRand, CRnand, CRor, crxor.
 whatever you need.

i kinda feel... it's hard to describe.  respectful of the sheer quantity of
work that went into VSX, slightly horrified as well, and quite
uncomfortable even just reading the pseudocode.

l.




-- 
---
crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68


More information about the Libre-soc-dev mailing list