[Libre-soc-dev] All div pipe tests pass

[Luke Kenneth Casson Leighton]

On 10/7/20, Jacob Lifshay <programmerjake at gmail.com> wrote:
> On Wed, Oct 7, 2020, 05:22 Luke Kenneth Casson Leighton <lkcl at lkcl.net>
> wrote:
>
>> On Wed, Oct 7, 2020 at 6:00 AM Jacob Lifshay <programmerjake at gmail.com>
>> wrote:
>> >
>> > On Tue, Oct 6, 2020 at 9:42 PM Luke Kenneth Casson Leighton
>> > <lkcl at lkcl.net> wrote:
>> > >
>> > > On 10/7/20, Jacob Lifshay <programmerjake at gmail.com> wrote:
>> > > > I got all the div fu tests to pass by fixing the ISA spec and fixing
>> > > > the one bug I found in the div fu.
>> > >
>> > > briiiliant.
>> > >
>> > > that's good in two ways because we can propose the pseudocode for a
>> v3.0C spec.
>> >
>> > Still need to convert all `undefined` references in those instructions
>> > to 0 bits though.
>>
>> i "solved" that one by (in the simulator) defining the variable
>> "undefined" to 0b00000000000000000000000000000000...
>>
>> proposing to OPF two inter-related things at once is probably not a
>> good idea.  they should really be separate discussions, not least
>> because the variable named "undefined" is used in multiple places.
>>
>
> My plan for div is to just remove references to undefined, not removing the
> definition of undefined.

the thought of removing "undefined" without the OpenPower Foundation's
ISA WG approval has me slightly alarmed.

yes there is "pressure to do so" however we can use that "pressure" to
make the case that it should be *officially* removed from the spec.

if we diverge the pseudocode without authorisation we lose their
good-will and respect.

best to do the two proposals completely separate.

l.