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From: Andy Shevchenko <andy.shevchenko@gmail.com>
Date: Sun, 7 Jan 2024 21:46:24 +0200
Message-ID: <CAHp75VfiTCCa+Rjn4JavxvSziNmjBTXEgUq-UT+PHkD8__5dhw@mail.gmail.com>
Subject: Re: drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
To: wens@csie.org
Cc: kernel test robot <lkp@intel.com>, Aidan MacDonald <aidanmacdonald.0x0@gmail.com>, 
	oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org, 
	Jonathan Cameron <Jonathan.Cameron@huawei.com>
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On Sun, Jan 7, 2024 at 7:37=E2=80=AFAM Chen-Yu Tsai <wens@csie.org> wrote:
> On Sun, Jan 7, 2024 at 9:30=E2=80=AFAM kernel test robot <lkp@intel.com> =
wrote:

...

> > sparse warnings: (new ones prefixed by >>)
> > >> drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
> >    drivers/iio/adc/axp20x_adc.c:577:26: sparse: sparse: dubious: x & !y
>
> This looks like a false positive. The code is doing exactly what we want:
> val =3D val ? 1 : 0, but in a shorter format.

Yes, but the problem is that FIELD_PREP() is a macro.
You can replace these by ternary (here and in other cases) to satisfy
sparse. Compiler will optimize that anyway, so no branch is expected
in the generated code.

--=20
With Best Regards,
Andy Shevchenko