On 23.08.2024 01:06, Andrew Cooper wrote:
> ... and drop generic_hweight64().
>
> This is identical on all architectures except ARM32. Add one extra SELF_TEST
> to check that hweight64() works when the input is split in half.
>
> No functional change.
>
> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
with one remark:
> --- a/xen/include/xen/bitops.h
> +++ b/xen/include/xen/bitops.h
> @@ -302,6 +302,14 @@ static always_inline __pure unsigned int
> hweightl(unsigned long x)
> #endif
> }
>
> +static always_inline __pure unsigned int hweight64(uint64_t x)
> +{
> + if ( BITS_PER_LONG == 64 )
> + return hweightl(x);
> + else
> + return hweightl(x >> 32) + hweightl(x);
This assume BITS_PER_LONG == 32, which of course is true right now, but
doesn't need to be in general. Better add an explicit cast to uint32_t
(or masking by 0xffffffffU)?
Jan
