[Libre-soc-dev] setvl lost its reserved fields (was: setvl gaining CTR mode)

[Jacob Lifshay]

On Sun, Jul 3, 2022, 04:04 lkcl <luke.leighton at gmail.com> wrote:

> even Jacob's idea to use one bit of SVi would have serious knock-on
> implications in binutils, unit tests, ISACaller, and TestIssuer, because
> that "one bit" has to be excluded from being allowed to be used. syntax
> errors raised at the bare minimum in binutils.
>

imho syntax errors (or any other binutils changes) aren't strictly
necessary --
this is like *(int *)1 in c isn't a syntax error though it is most likely
UB.

imho, ever since SVi became a 7-bit field again, the MSB is required to be
a zero (otherwise MVL and VL would get set to 65 or greater). if we don't
check that, wether or not my spec change is applied, the code is just plain
wrong.

my change is merely making that explicit in the spec.

Jacob