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SubjectRe: [PATCH 29/54] drivers/iio: replace bitmap_weight() with bitmap_weight_{eq,gt} where appropriate
On Mon, 24 Jan 2022 14:46:43 +0200
Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> On Sun, Jan 23, 2022 at 10:39:00AM -0800, Yury Norov wrote:
> > drivers/iio calls bitmap_weight() to compare the weight of bitmap with
> > a given number. We can do it more efficiently with bitmap_weight_{eq, gt}
> > because conditional bitmap_weight may stop traversing the bitmap earlier,
> > as soon as condition is met.
>
> ...
>
> > int i, j;
> >
> > for (i = 0, j = 0;
> > - i < bitmap_weight(indio_dev->active_scan_mask,
> > - indio_dev->masklength);
> > + bitmap_weight_gt(indio_dev->active_scan_mask,
> > + indio_dev->masklength, i);
> > i++, j++) {
> > j = find_next_bit(indio_dev->active_scan_mask,
> > indio_dev->masklength, j);
>
> This smells like room for improvement. Have you checked this deeply?
>

I have no idea what I was smoking that day.
It was near 10 years ago, so I'll blame my younger self ;)

Jonathan

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