On Wed, Feb 28, 2024 at 05:39:21PM -0600, Lucas De Marchi wrote:
On Thu, Feb 22, 2024 at 06:49:59AM -0800, Yury Norov wrote:
> On Wed, Feb 21, 2024 at 03:59:06PM -0600, Lucas De Marchi wrote:
> > On Wed, Feb 21, 2024 at 11:04:22PM +0200, Andy Shevchenko wrote:
> > > On Wed, Feb 21, 2024 at 10:30:02PM +0200, Dmitry Baryshkov wrote:
> > > > On Thu, 8 Feb 2024 at 09:45, Lucas De Marchi <lucas.demarchi@xxxxxxxxx> wrote:
...
I build-tested this in x86-64, x86-32 and arm64. I didn't like much the
need to fork the __GENMASK() implementation on the 2 sides of the ifdef
since I think the GENMASK_INPUT_CHECK() should be the one covering the
input checks. However to make it common we'd need to solve 2 problems:
the casts and the sizeof. The sizeof can be passed as arg to
__GENMASK(), however the casts I think would need a __CAST_U8(x)
or the like and sprinkle it everywhere, which would hurt readability.
Not pretty. Or go back to the original submission and make it less
horrible :-/
I'm wondering if we can use _Generic() approach here.
...
> #define GENMASK_INPUT_CHECK(h, l) 0
> +#define __GENMASK(t, h, l) \
> + ((~0 - (1 << (l)) + 1) & (~0 >> (BITS_PER_LONG - 1 - (h))))
humn... this builds, but does it work if GENMASK_ULL() is used in
assembly? That BITS_PER_LONG does not match the type width.
UL()/ULL() macros are not just for fun.
--
With Best Regards,
Andy Shevchenko