Re: Linux 5.19-rc8

From: Yury Norov
Date: Tue Jul 26 2022 - 11:51:52 EST


On Mon, Jul 25, 2022 at 01:40:58PM -0700, Linus Torvalds wrote:
> On Mon, Jul 25, 2022 at 1:35 PM Yury Norov <yury.norov@xxxxxxxxx> wrote:
> >
> > Here we have 2 ugly options - having pairs of almost identical
> > functions, or passing dummy variables. I decided that copy-pasting is
> > worse than abusing branch predictor.
>
> The thing is, we have solutions for this - just use a single inline
> function, and make it *see* the constant.
>
> That way the compiler can DTRT, either generating two copies (with the
> constant elided) or depending on the branch predictor.
>
> That's particularly true in a case like this, when there is only *one*
> case for the normal situation (ie little-endian). Because let's face
> it, big-endian is completely dead and legacy model.

OK, I'll do it for 5.20. Thanks for the hint.