Messages in this thread | | | From | Andy Shevchenko <> | Date | Wed, 13 Jul 2022 22:14:24 +0200 | Subject | Re: [PATCH 3/6] bitops: bitmap helper to set variable length values |
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On Wed, Jul 13, 2022 at 9:44 PM Yury Norov <yury.norov@gmail.com> wrote: > On Wed, Jul 13, 2022 at 09:10:33PM +0200, Andy Shevchenko wrote: > > On Wed, Jul 13, 2022 at 8:56 PM Yury Norov <yury.norov@gmail.com> wrote: > > > On Wed, Jul 13, 2022 at 06:31:59PM +0200, Sebastian Fricke wrote: > > > > ... > > > > > I'd suggest you to try implementing > > > bitmap_copy_from(dst, src, dst_off, len) > > > or even > > > bitmap_copy_from(dst, dst_off, src, src_off, len) > > > if you expect that you'll need more flexibility in the future. > > > > Do you think it would be useful? > > > > We have bitmap_replace() & bitmap_remap(). Wouldn't that be enough? > > bitmap_replace and bitmap_remap have no an 'offset' parameter.
True.
But then it's a bit too generic to have this src_off, no?
I would rather expect for asymmetrical bitmaps that the other side will be either one of the fixed width types (it makes sense to have for 32- or 64-bit arguments.
When you have a source bitmap of x bits and you would like to copy it into a y-bit one, I would think that either you have a small amount of bits in x anyway, or x is a full-sized bitmap (same order as y). Also keep in mind that granularity is long, so less than long it makes no sense.
bitmap_copy_from_T(unsigned long *map, start, len, T src),
where T is type, start is the offset in map, len is the amount of bits from src starting from 0. That's what is required in most of the cases I believe.
-- With Best Regards, Andy Shevchenko
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