Re: [Qemu-devel] [PATCH 12/38] tcg: Add gvec expanders for variable shift

[David Hildenbrand]

On 23.04.19 21:28, Richard Henderson wrote:
> On 4/23/19 12:04 PM, David Hildenbrand wrote:
>> In order to use this on s390x for VECTOR ELEMENT SHIFT, like
>>
>> +static DisasJumpType op_vesv(DisasContext *s, DisasOps *o)
>> +{
>> +    const uint8_t es = get_field(s->fields, m4);
>> +    const uint8_t v1 = get_field(s->fields, v1);
>> +    const uint8_t v2 = get_field(s->fields, v2);
>> +    const uint8_t v3 = get_field(s->fields, v3);
>> +
>> +    if (es > ES_64) {
>> +        gen_program_exception(s, PGM_SPECIFICATION);
>> +        return DISAS_NORETURN;
>> +    }
>> +
>> +    switch (s->fields->op2) {
>> +    case 0x70:
>> +        gen_gvec_fn_3(shlv, es, v1, v2, v3);
>> +        break;
>> +    case 0x7a:
>> +        gen_gvec_fn_3(sarv, es, v1, v2, v3);
>> +        break;
>> +    case 0x78:
>> +        gen_gvec_fn_3(shrv, es, v1, v2, v3);
>> +        break;
>> +    default:
>> +        g_assert_not_reached();
>> +    }
>> +
>> +    return DISAS_NEXT;
>> +}
>>
>> We need to mask of invalid bits from the shift. Can that be added?
> 
> Yes, I do exactly this in patch 31 for target/ppc.
> 
> 
> r~
> 

Got it, so not via a generic gvec expansion. Thanks!

-- 

Thanks,

David / dhildenb