Re: [PATCH 23/37] target/i386: reimplement 0x0f 0x78-0x7f, add AVX

[Paolo Bonzini]

On Mon, Sep 12, 2022 at 3:56 PM Richard Henderson
<richard.henderson@linaro.org> wrote:

> > +static void gen_SSE4a_I(DisasContext *s, CPUX86State *env, X86DecodedInsn 
> > *decode)
> > +{
> > +    TCGv_i32 length = tcg_const_i32(decode->immediate & 255);
> > +    TCGv_i32 index = tcg_const_i32(decode->immediate >> 8);
> > +
> > +    if (s->prefix & PREFIX_DATA) {
> > +        gen_helper_extrq_i(cpu_env, s->ptr0, index, length);
> > +    } else {
> > +        gen_helper_insertq_i(cpu_env, s->ptr0, index, length);
> > +    }
> > +    tcg_temp_free_i32(length);
> > +    tcg_temp_free_i32(index);
>
> Again, why the choice of delayed decode?  I guess it doesn't matter, but it's 
> odd.

Mostly because I wasn't sure of which would be preferable so I tried
different things. I think now I have a better picture.

I will mostly switch to decode_by_prefix.

Paolo