Re: [Lightning] About 32 and 64 bits registers

[Paulo Cesar Pereira de Andrade]

On 24-08-2010 04:02, Paolo Bonzini wrote:
> On 08/24/2010 05:18 AM, Paulo César Pereira de Andrade wrote:
>
> > Back to the issue of 32/64 bits registers, I think the proper solution
> > probably would be more like:
> >
> > jit_movi_i vs jit_movi_l vs jit_movi_ui vs jit_movi_ul
> >
> > Now that the _{u,}l versions exist, maybe it would not be wise to
> > remove them, but just make them an alias, but, the 'i' should be
> > understood as (i)mmediate, and the ui as (u)nsigned (i)mmediate.
> > Same thing would apply to branches, e.g. jit_bltr_i would mean
> > jit_branch_if_less_than(label, register, immediate)
>
> No, there is a misunderstanding. jit_bltr_i means

  Oops, yes, jit_blti_{i,ui,l,ul,p}. The real problem is with
jit_movi_{i,ui,l,ul,p}, that, like a load, must sign/zero extend
the register, or weird things may happen. Branches may become
tricky, this is why I am making the test cases, as one may depend
of behavior on overflow.

> Branch
> if Less Than Register
> operand size = Integer
>
> In general all operations are
> : jit_XXXr_TT register <- register OP register, signed type TT
> : jit_XXXi_TT register <- register OP immediate, signed type TT
> : jit_XXXr_uTT register <- register OP register, unsigned type TT
> : jit_XXXi_uTT register <- register OP immediate, unsigned type TT
>
> Your other patches are fine and I'll merge them soon.

  Thanks, as said in the other email I will remake them, and resend
shortly.

> Paolo

Paulo