Re: [PATCH v2 41/71] target/arm: Add infrastructure for disas_sme

[Peter Maydell]

On Thu, 9 Jun 2022 at 23:58, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 6/9/22 08:35, Peter Maydell wrote:
> >> +        if (!disas_sme(s, insn)) {
> >> +            unallocated_encoding(s);
> >> +        }
> >> +        break;
> >
> > I still think we should check bit 31 here.
>
> We don't do anything similar over in a32, where we've done the full 
> conversion:
>
>          if (disas_a32_uncond(s, insn) ||
>
>              disas_vfp_uncond(s, insn) ||
>
>              disas_neon_dp(s, insn) ||
>
>              disas_neon_ls(s, insn) ||
>
>              disas_neon_shared(s, insn)) {
>
>              return;
>
>          }

The difference there is that we've basically completed the decodetree
conversion. Here we're putting one decodetree disas call inside a
legacy decode, so we should put it at the right point in the
legacy structure, I think.

> and there's nothing else within major opcode 0 to conflict.

Yet :-)

-- PMM