Re: [PATCH 04/14] target/s390x: Fix ICM with M3=0

[David Hildenbrand]

On 18.07.23 23:21, Ilya Leoshkevich wrote:
> When the mask is zero, access exceptions should still be recognized for
> 1 byte at the second-operand address. CC should be set to 0.
>
> Cc: qemu-stable@nongnu.org
> Fixes: e023e832d0ac ("s390x: translate engine for s390x CPU")
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
>   target/s390x/tcg/translate.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
> index 2f61e879878..2d7cc8963b4 100644
> --- a/target/s390x/tcg/translate.c
> +++ b/target/s390x/tcg/translate.c
> @@ -2516,6 +2516,12 @@ static DisasJumpType op_icm(DisasContext *s, DisasOps *o)
>           len = 8;
>           goto one_insert;
>   
> +    case 0:
> +        /* Recognize access exceptions for the first byte.  */
> +        tcg_gen_qemu_ld_i64(tmp, o->in2, get_mem_index(s), MO_UB);
> +        gen_op_movi_cc(s, 0);
> +        return DISAS_NEXT;
> +
>       one_insert:
>           pos = base + ctz32(m3) * 8;
>           tcg_gen_deposit_i64(o->out, o->out, tmp, pos, len);

That label in there is really nasty.

I would just have but the "case 0" right at the top (or right in front 
of the "default") and left all of that nasty stuff involving that label 
alone.

Reviewed-by: David Hildenbrand <david@redhat.com>

--
Cheers,

David / dhildenb