On 13.04.19 02:54, Richard Henderson wrote:
> On 4/11/19 12:08 AM, David Hildenbrand wrote:
>> +static DisasJumpType op_vsldb(DisasContext *s, DisasOps *o)
>> +{
>> + int src_idx = get_field(s->fields, i4) & 0xf;
>> +
>> + if (src_idx == 0) {
>> + gen_gvec_mov(get_field(s->fields, v1), get_field(s->fields, v2));
>> + } else {
>> + gen_gvec_3_ool(get_field(s->fields, v1), get_field(s->fields, v2),
>> + get_field(s->fields, v3), src_idx,
>> + gen_helper_gvec_vsldb);
>> + return DISAS_NEXT;
>
> You could also expand this inline using your new extract2 primitive.
>
> int i4 = get_field(s->fields, i4);
> int left_shift, right_shift;
>
> left_shift = (i4 & 7) * 8;
> right_shift = 64 - left_shift;
>
> if ((i4 & 8) == 0) {
> read_vec_element_i64(t0, get_field(s->fields, v2), 0, ES_64);
> read_vec_element_i64(t1, get_field(s->fields, v2), 1, ES_64);
> read_vec_element_i64(t2, get_field(s->fields, v3), 0, ES_64);
> } else {
> read_vec_element_i64(t0, get_field(s->fields, v2), 1, ES_64);
> read_vec_element_i64(t1, get_field(s->fields, v3), 0, ES_64);
> read_vec_element_i64(t2, get_field(s->fields, v3), 1, ES_64);
> }
> tcg_gen_extract2_i64(t0, t1, t0, right_shift);
> tcg_gen_extract2_i64(t1, t2, t1, right_shift);
Trying to understand the magic, left_shift is really only used to to
calculate right_shift, right?
> write_vec_element_i64(t0, get_field(s->fields, v1), 0, ES_64);
> write_vec_element_i64(t1, get_field(s->fields, v1), 1, ES_64);
>
>
> r~
>
--
Thanks,
David / dhildenb
