[Info-vax] Listeners in VMS Basic, was: Re: Integrity iLO Configuration?

[abrsvc]

On Monday, July 12, 2021 at 11:02:35 AM UTC-4, Arne Vajhøj wrote:
> On 7/12/2021 1:34 AM, Simon Clubley wrote: 
> > On 2021-07-10, abrsvc <dansabr... at yahoo.com> wrote: 
> >>> But I wonder why MOVZWL and not just MOVL! 
> >>
> >> IRRC, the MOVZWL will take less memory since the immediate value will be smaller. 
> > 
> > It would be amusing if the more efficient sequences get translated 
> > to less efficient sequences on Alpha and above when using the Macro-32 
> > compiler and if a less efficient sequence on VAX actually translates 
> > to a more efficient sequence on Alpha and above. :-)
> On Alpha both end up as: 
> 
> MOV 1, R0 
> 
> Arne

There is no "mov" on Alpha.  What you will end up with is a load/store combination.

On VAX, the use of MOVZBL or MOVZWL with the first argument being in immediate mode will reserve that size for the immediate value.  In other words if the immediate value is 2, the MOVZBL #2,R0 will result in the immediate value consuming 1 byte for the 2 where the MOZWL instruction with the same arguments will consume 2 bytes for the value 2.

Dan