[Libre-soc-dev] LD/ST Elwidth Overrides

[Jacob Lifshay]

On Wed, Sep 1, 2021, 12:10 lkcl <luke.leighton at gmail.com> wrote:

>
>
> On September 1, 2021 6:41:27 PM UTC, Jacob Lifshay <
> programmerjake at gmail.com> wrote:
>
> >so, the reserved combination is signed, and everything else is
> >unsigned?
>
> (trim!! please! :)
>

(there wasn't much, so I left it in)


The index-reg elwidth override should apply even when all regs are scalar
(that's how webassembly will use it).

also, we should mark ffirst as banned when either base and/or index
registers are vectors. the table implies ffirst is only banned when the
index reg is vectorized:
 imm(RA)  RT.v   RA.v   no stride allowed
 imm(RA)  RT.s   RA.v   no stride allowed
 imm(RA)  RT.v   RA.s   stride-select allowed
 imm(RA)  RT.s   RA.s   not vectorised
 RA,RB    RT.v  RA/RB.v ffirst banned
 RA,RB    RT.s  RA/RB.v ffirst banned
 RA,RB    RT.v  RA/RB.s VSPLAT possible
 RA,RB    RT.s  RA/RB.s not vectorized

Jacob