Re: New Vax - future directions :-)

[Jason Thorpe <thorpej%me.com@localhost>]

> On Jul 5, 2021, at 3:17 PM, Johnny Billquist <bqt%update.uu.se@localhost> wrote:
> 
> On 2021-07-05 23:03, Jason Thorpe wrote:
>>> On Jul 5, 2021, at 12:18 PM, Mouse <mouse%Rodents-Montreal.ORG@localhost> wrote:
>>> 
>>> 
>>> It clears R0 and R1.  On VAX-32, that is.  It remains to be determined
>>> what it would do on VAX-64 (in 64-bit mode, if the hardware is to be
>>> dual-mode).  Personally, I would say it should clear just R0 (but all
>>> 64 bits of it).
>> IMO, CLRQ should be disallowed in 32-bit mode.
> 
> I think you are about 45 years late for that one. :-D

Ok, let me re-state… “for any Q insn that does not already exist, trying to use it in 32-bit mode should cause an illegal insn fault”.

The idea that an operation that takes a single register as an argument would operate on two is, frankly, stupid.

-- thorpej