Re: [PATCH] include/linux/slab.h: use for() and left shift to calculate

[Yejune Deng]

Thank you. I hadn't thought of that。

On Tue, Mar 2, 2021 at 5:09 PM Christoph Lameter <cl@xxxxxxxxx> wrote:
>
> On Tue, 2 Mar 2021, Yejune Deng wrote:
>
> > use for() and left shift to calculate the value that compared with size.
>
> There is a reason for the madness...
>
> The current code was written so compilers can do proper constant folding
> and eliminate the whole function entirely.
>
> If you want this change then please verify that all compilers currently in
> use with this code do proper constant folding and never generate code for
> the for loop.