On 1/15/21 3:18 PM, Vincent MAILHOL wrote:
> On Fri. 15 janv. 2021 at 22:51, Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote:
>> On 1/15/21 2:20 PM, Vincent MAILHOL wrote:
>>> /* map the data length to an appropriate data length code */
>>> u8 can_fd_len2dlc(u8 len)
>>> {
>>> switch(len) {
>>> case 0 ... 8:
>>> return len;
>>> case 9 ... 12:
>>> return 9;
>>> case 13 ... 16:
>>> return 10;
>>> case 17 ... 20:
>>> return 11;
>>> case 21 ... 24:
>>> return 12;
>>> case 25 ... 32:
>>> return 13;
>>> case 33 ... 48:
>>> return 14;
>>> case 49 ... 64:
>>> default:
>>> return CANFD_MAX_DLC;
>>> }
>>> }
>>>
>>> And we will just leave the optimizations in the hand of the compiler.
>>
>> I've already tried this. It results in a longer object file on ARM, even if you
>> remove the array....
>
> You are right. I just checked the assembly code: it does a
> dichotomy which means that in addition to being bigger, it is
> also slower.
>
> Please forget my previous message, it wasn't really smart.
I had the same idea, as I've never used these new cases I tried it out and was
underwhelmed. At least compared to this tightly packed array.
Marc
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