Re: [PATCH 29/33] target/ppc: implemented XXSPLTI32DX

[Richard Henderson]

On 10/21/21 12:45 PM, matheus.ferst@eldorado.org.br wrote:
> From: "Bruno Larsen (billionai)" <bruno.larsen@eldorado.org.br>
>
> Implemented XXSPLTI32DX emulation using decodetree
>
> Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
> Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
> ---
>   target/ppc/insn64.decode            | 11 ++++++++
>   target/ppc/translate/vsx-impl.c.inc | 41 +++++++++++++++++++++++++++++
>   2 files changed, 52 insertions(+)
>
> diff --git a/target/ppc/insn64.decode b/target/ppc/insn64.decode
> index 880ac3edc7..8d8d5d5729 100644
> --- a/target/ppc/insn64.decode
> +++ b/target/ppc/insn64.decode
> @@ -32,6 +32,14 @@
>                   ...... ..... ra:5 ................       \
>                   &PLS_D si=%pls_si rt=%rt_tsxp
>   
> +# Format 8RR:D
> +%8rr_si         32:s16 0:16
> +%8rr_xt         16:1 21:5
> +&8RR_D_IX       xt ix si:int32_t

What is it about this field that says signed, expecially?  It doesn't seem wrong, of 
course, but you are jumping through extra hoops here...

> +    get_cpu_vsrh(t0, a->xt);
> +    get_cpu_vsrl(t1, a->xt);
> +
> +    tcg_gen_movi_i64(new_val, a->si);
> +    if (a->ix) {
> +        tcg_gen_movi_i64(mask, 0x00000000ffffffff);
> +        tcg_gen_shli_i64(new_val, new_val, 32);
> +    } else {
> +        tcg_gen_movi_i64(mask, 0xffffffff00000000);
> +    }
> +    tcg_gen_and_i64(t0, t0, mask);
> +    tcg_gen_or_i64(t0, t0, new_val);
> +    tcg_gen_and_i64(t1, t1, mask);
> +    tcg_gen_or_i64(t1, t1, new_val);
> +
> +    set_cpu_vsrh(a->xt, t0);
> +    set_cpu_vsrl(a->xt, t1);

You're working too hard here.  I think you should just store the two int32_t at the 
correct offsets.  And failing that, use tcg_gen_deposit_i64.


r~