Re: [PATCH 5/8] bitsperlong.h: introduce SMALL_CONST() macro

Andy Shevchenko
2021-02-01T13:47:16Z

On Sat, Jan 30, 2021 at 11:17:16AM -0800, Yury Norov wrote:
> Many algorithms become simpler if they are passed with relatively small
> input values. One example is bitmap operations when the whole bitmap fits
> into one word. To implement such simplifications, linux/bitmap.h declares
> small_const_nbits() macro.
>
> Other subsystems may also benefit from optimizations of this sort, like
> find_bit API in the following patches. So it looks helpful to generalize
> the macro and extend it's visibility.

Hmm... Are we really good to allow 0 as a parameter to it? I remember we had
a thread at some point where Rasmus explained why 0 is excluded.

...

> --- a/tools/include/asm-generic/bitsperlong.h
> +++ b/tools/include/asm-generic/bitsperlong.h

Tools part in a separate patch?

--
With Best Regards,
Andy Shevchenko