Re: [PATCH v3 01/14] target/s390x: Make CKSM raise an exception if R2 is odd

[Richard Henderson]

On 7/19/23 23:11, Ilya Leoshkevich wrote:
> R2 designates an even-odd register pair; the instruction should raise
> a specification exception when R2 is not even.
>
> Cc: qemu-stable@nongnu.org
> Fixes: e023e832d0ac ("s390x: translate engine for s390x CPU")
> Reviewed-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
>   target/s390x/tcg/translate.c | 11 +++++++++--
>   1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
> index 6661b27efa4..2f61e879878 100644
> --- a/target/s390x/tcg/translate.c
> +++ b/target/s390x/tcg/translate.c
> @@ -1991,11 +1991,18 @@ static DisasJumpType op_cxlgb(DisasContext *s, DisasOps 
> *o)
>   static DisasJumpType op_cksm(DisasContext *s, DisasOps *o)
>   {
>       int r2 = get_field(s, r2);
> -    TCGv_i128 pair = tcg_temp_new_i128();
> -    TCGv_i64 len = tcg_temp_new_i64();
> +    TCGv_i128 pair;
> +    TCGv_i64 len;
> +
> +    if (r2 & 1) {
> +        gen_program_exception(s, PGM_SPECIFICATION);
> +        return DISAS_NORETURN;
> +    }

Ideally, SPEC_r2_even would be set, handling this earlier.
Perhaps adding an "in2_ra2_E" might be helpful?


r~