Re: [PATCH 10/13] target/riscv/insn_trans/trans_rvv.c.inc: use 'vlenb' in MAXSZ()

[Daniel Henrique Barboza]

On 1/12/24 19:45, Richard Henderson wrote:
> On 1/13/24 08:38, Daniel Henrique Barboza wrote:
> > MAXSZ() returns the value in bytes. Now that we have access to vlenb
> > we don't need to compensate with a '-3' in the scale to use 'vlen'.
> >
> > MAXSZ() now works as follows:
> >
> > LMUL  lmul=scale  MAXSZ (vlenb >> -scale)
> >    1       0       vlenb
> >    2       1       vlenb << 1
> >    4       2       vlenb << 2
> >    8       3       vlenb << 3
>
> Um, what?
>
> >   static inline uint32_t MAXSZ(DisasContext *s)
> >   {
> > -    int scale = s->lmul - 3;
> > -    return s->cfg_ptr->vlen >> -scale;
> > +    return s->cfg_ptr->vlenb >> -s->lmul;
>
> There's no left-shift here, either before or after.
> Bug?

Yeah, I got lost in that explanation. I'll simplify it to be just a simple case 
of
adjusting the right shift to use vlenb like in patches 8 and 9.


Thanks,


Daniel



> r~