Re: [Qemu-devel] [PATCH v5 2/2] target/mips: Optimize ILVEV.<B|H|W|D> MSA instructions

[Richard Henderson]

On 4/3/19 5:28 AM, Aleksandar Markovic wrote:
>> +    tcg_gen_andi_i64(t1, msa_wr_d[wt * 2], mask);
>> +    tcg_gen_deposit_i64(msa_wr_d[wd * 2], t1, msa_wr_d[ws * 2], 32, 32);
>> +
>> +    tcg_gen_andi_i64(t1, msa_wr_d[wt * 2 + 1], mask);
>> +    tcg_gen_deposit_i64(msa_wr_d[wd * 2 + 1], t1, msa_wr_d[ws * 2 + 1], 32, 
>> 32);
>> +
>> +    tcg_temp_free_i64(t1);
>> +}
>> +
> 
> This can be further optimized this way: (doublecheck the accuracy, writing 
> from
> home)
> 
> gen_ilvev_w(CPUMIPSState *env, uint32_t wd,
>                                 uint32_t ws, uint32_t wt)
> {
>     tcg_gen_shli_i64(msa_wr_d[wd * 2], msa_wr_d[ws * 2], 32);
>     tcg_gen_deposit_i64(msa_wr_d[wd * 2], t1, msa_wr_d[wt * 2], 0, 32);
> 

No, the shift can be performed by the deposit.
See my other reply in this thread.


r~