Re: [PATCH v2 12/15] tcg/arm: Implement TCG_TARGET_HAS_bitsel_vec

[Richard Henderson <richard.henderson@linaro.org>]

On 2/8/21 11:55 AM, Peter Maydell wrote:
> On Mon, 8 Feb 2021 at 04:02, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> NEON has 3 instructions implementing this 4 argument operation,
>> with each insn overlapping a different logical input onto the
>> destination register.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> @@ -2899,6 +2904,18 @@ static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc,
>>          }
>>          return;
>>
>> +    case INDEX_op_bitsel_vec:
>> +        a3 = args[3];
>> +        if (a0 == a3) {
>> +            tcg_out_vreg3(s, INSN_VBIT, q, 0, a0, a2, a1);
>> +        } else if (a0 == a2) {
>> +            tcg_out_vreg3(s, INSN_VBIF, q, 0, a0, a3, a1);
>> +        } else {
>> +            tcg_out_mov(s, type, a0, a1);
> 
> Side note: aarch64 tcg guards this tcg_out_mov with "if (a0 != a1)",
> which if I understand correctly is superfluous and could be removed.

Yep, tcg_out_mov already does that test.


r~