[PATCH v2] erofs-utils: lib: converted division to shift in z_erofs_load_compact_lcluster

[Gao Xiang]

On 2026/2/27 07:37, Ashley Lee wrote:
> On Wed, 25 Feb 2026 at 18:40, Gao Xiang <hsiangkao at linux.alibaba.com> wrote:
>>
>>
>>
>> On 2026/2/26 10:32, Yifan Zhao wrote:
>>>
>>> A quick search shows that x86 kernel implementation also use `div` instruction
>>>
>>> under Linux v6.19 and GCC 15.2.1, add GCC correctly generate shift instruction
>>
>> Could we try more GCC versions and find the impacts?
>>
>> Does it a recent GCC regression?
>>
>>
>>>
>>> in my arm64 machine with GCC 14.2.0.
>>>
>>> Could you also consider evaluate this optimization in kernel?
>>
>> Yes, but I wonder if `div` is already used for these years on x86,
>> could you check this?
> 
> Hello all,
> 
> I'll attempt to perform benchmarks on as many architectures and
> compiler variants as I can. I was looking into lkp-tests to perform
> this however I was facing trouble running on my OS. Is there a
> simple way to do this?

I never customize lkp-tests, but I guess just triggering fio on
common platfroms with a given dataset (like enwik9) is enough.

Thanks,
Gao Xiang

> 
> Thank you,
> 
> Ashley