Re: [PATCH 5/8] target/ppc: Move multiply fixed-point insns (64-bit operands) to decodetree.

[Chinmay Rath <rathc@linux.vnet.ibm.com>]

Hi Richard,

On 4/17/24 00:06, Richard Henderson wrote:
> On 4/15/24 23:39, Chinmay Rath wrote:
>> +static bool trans_MADDHDU(DisasContext *ctx, arg_MADDHDU *a)
> ...
>> +    tcg_gen_movi_i64(t1, 0);
>
> Drop the movi.
>
>> +    tcg_gen_add2_i64(t1, cpu_gpr[a->vrt], lo, hi, cpu_gpr[a->rc], t1);
>
> Use tcg_constant_i64(0).
>
Looks like tcg_gen_add2_i64 internally modifies the passed arguments, 
hence constant is not expected.
However, I tried using tcg_constant_i64(0) as suggested but this leads 
to an assert failure :
qemu-system-ppc64: ../tcg/tcg.c:5071: tcg_reg_alloc_op: Assertion 
`!temp_readonly(ts)' failed.

So I hope it is fine to keep the code change as is for now.
Let me know if you have any suggestions.

Thanks,
Chinmay
> With that,
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
>
>
> r~