Re: [PATCH v8 03/17] xen/bitops: implement fls{l}() in common logic

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

On Thu, 2024-04-25 at 17:44 +0200, Jan Beulich wrote:
> On 17.04.2024 12:04, Oleksii Kurochko wrote:
> > Return type was left 'int' because of the following compilation
> > error:
> > 
> > ./include/xen/kernel.h:18:21: error: comparison of distinct pointer
> > types lacks a cast [-Werror]
> >        18 |         (void) (&_x == &_y);            \
> >           |                     ^~
> >     common/page_alloc.c:1843:34: note: in expansion of macro 'min'
> >      1843 |         unsigned int inc_order = min(MAX_ORDER, flsl(e
> > - s) - 1);
> 
> Apart from this I'm okay with this patch, assuming Andrew's won't
> change in
> any conflicting way. As to the above - no, I don't see us having
> ffs() / ffsl()
> returning unsigned int, fls() / flsl() returning plain int. Even more
> so that,
> given the LHS variable's type, an unsigned quantity is really meant
> in the
> quoted code.
If I understand you correctly, it's acceptable for fls() / flsl() to
return 'int'. Therefore, I can update the commit message by removing
the part mentioning the compilation error, as it's expected for fls() /
flsl() to return 'int'. Is my understanding correct?

~ Oleksii