[Libre-soc-dev] scalar instructions and SVP64

Jacob Lifshay programmerjake at gmail.com
Wed Mar 10 01:05:02 GMT 2021


On Tue, Mar 9, 2021, 16:50 Luke Kenneth Casson Leighton <lkcl at lkcl.net>
wrote:

> On Wednesday, March 10, 2021, Jacob Lifshay <programmerjake at gmail.com>
> wrote:
>
> > https://libre-soc.org/irclog/%23libre-soc.2021-03-10.log.
> > html#t2021-03-10T00:11:21
> >
> > You see why we need VL to be ignored when there aren't any vector
> > arguments?
>
>
> late (1am), the short answer is no.
>

Well, then we need to change the spec since a "no" answer is effectively
unworkable from a SW perspective, as (poorly) illustrated by that example
code. in compilers, and most the rest of SW, vector and scalar are two
different classes of operations/types/values/etc. SV needs to be modified
to account for that. scalar being just element 0 of a vector is deceptively
alluring, but is really a trap.

We can discuss in further detail after you get some sleep.

Jacob


More information about the Libre-soc-dev mailing list