On 01.10.20 17:26, Richard Henderson wrote:
> On 9/30/20 9:55 AM, David Hildenbrand wrote:
>> + /* Multipy both even elements from v2 and v3 */
>> + read_vec_element_i64(l1, get_field(s, v2), 0, ES_64);
>> + read_vec_element_i64(h1, get_field(s, v3), 0, ES_64);
>> + tcg_gen_mulu2_i64(l1, h1, l1, h1);
>> + /* Shift result left by one bit if requested */
>> + if (extract32(get_field(s, m6), 3, 1)) {
>> + tcg_gen_extract2_i64(h1, l1, h1, 63);
>> + tcg_gen_shli_i64(l1, l1, 1);
>> + }
>
> Not a bug, but some hosts require 3 insns for extract2 (so 4 total for this
> sequence).
>
> This doubling can also be had via add2:
>
> tcg_gen_add2_i64(l1, h1, l1, h1, l1, h1);
Took me longer than it should to realize this is really just doubling
the value ... will use tcg_gen_add2_i64() and add a comment.
Thanks!
--
Thanks,
David / dhildenb
