[Libre-soc-dev] funding & go-ahead requested for #1134

[Jacob Lifshay]

On Wed, Aug 16, 2023 at 9:56 PM Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:
> #1025.

I filled out the whole list of FP insns that were either in
openpower-isa.git or PowerISA v3.1B and broke them down into tasks,
grouping insns together as I think appropriate.

https://bugs.libre-soc.org/show_bug.cgi?id=1025#c0

Since it overlaps with the list in
https://bugs.libre-soc.org/show_bug.cgi?id=1026#c0 we need to figure
out what goes where.

>
> work out how much work is covered by each.  this will
> require you to do a time and budget estimation for
> the *whole* suite of instructions - every piece of
> sub-work.

IMO there are probably too many insns to fit in #1025/#1026, so we
need to decide what gets priority. I think we shouldn't bother
figuring out the budget for *absolutely everything*, but instead we
should figure out the budget for the things we're going to work on
next and leave the rest for later, or at least don't try to estimate
budget for things we decided won't fit in #1025/#1026, since we can
easily do that later when we have a better idea of what we need to do.

>
> if you need help with that, ask everyone else.
> (for each instruction you need to do a thought
> experiment "how many lines of HDL, how many unit tests"
> then from PAST EXPERIENCE estimate the total number
> of days.

that is non-linearly related to time needed, e.g. some insns may be
particularly tricky but not need a huge amount of code, other insns
may be extremely straightforward but verbose.

> assume 1 month is appx EUR 3000 and back-calculate.

ok, that's the figure that I didn't know until now, since iirc you
never stated it.

Jacob