Subject: Re: [PATCH v4 3/5] lib/bitmap: Introduce bitmap_scatter() and bitmap_gather() helpers

From: Herve Codina <[email-masked]>
Date: Thu, 22 Feb 2024 17:49:59 +0100

Hi Andy, Yury,

On Thu, 22 Feb 2024 17:39:27 +0200
Andy Shevchenko <[email-masked]> wrote:

...
> > + * bitmap_scatter() for the bitmap scatter detailed operations).  
> 
> > + * Suppose scattered computed using bitmap_scatter(scattered, src, mask, n).
> > + * The operation bitmap_gather(result, scattered, mask, n) leads to a result
> > + * equal or equivalent to src.  
> 
> This paragraph...
> 
> > + * The result can be 'equivalent' because bitmap_scatter() and bitmap_gather()
> > + * are not bijective.  
> 
> 
> > + * The result and src values are equivalent in that sense that a call to
> > + * bitmap_scatter(res, src, mask, n) and a call to bitmap_scatter(res, result,
> > + * mask, n) will lead to the same res value.  
> 
> ...seems duplicating this one.
> 
> I would drop the latter one.

I would like to give details about the 'equivalent' in this scatter/gather case.

If Yury is ok, I can drop this last paragraph.

Thanks for the review,

Regards,
Hervé