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Re: 6/8 bits imm instructions ( was Re: Rep:Re: [f-cpu] statisticsof direct indexing usage)



> > > like to use this particular combinaison?).
> >
> > uh uh, can you give me please some examples of such instruction ?
>
> It's the problčme of bit 12-13 (manual 0.2.5).
>
> It's use in the scan instruction to bit-reverse the input or negate it.
> It used as negate sign flag of the MAC instruction. All of this flag
> can't be used in the 8 bits immediat of such fonction. So is a pain or
> not ?

scan and mac doesn't use 12-13 (mac uses it for reg3) according
manual 2.7. And why do you want to use immediates for scan !?

So that for me is still seems you are interested to have immediates
for all insns (even for those where it makes no sense) and use
6 bits (register no) for it.

So I agree that it is possibly problem that 2 bits (8-6) can
go into needed flag region.
But still don't know what to do with it.
Did you mean to use 6bit immediate for insns which have no
room for 8bit imm and 8 bit for those whose have ?

> orthogonal. But in other hand, 8 bit is fewer than 6 :)

he !? :)

devik

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