From: Vincent Mailhol
> Sent: 02 December 2024 17:33
>
> In __clamp_once(),
>
> __builtin_choose_expr(__is_constexpr((lo) > (hi)), (lo) <= (hi), true)
>
> is equivalent to:
>
> !is_const_false((lo) <= (hi))
>
> Apply is_const_false() to simplify __clamp_once().
There is already a patch 'for next' that changes it use BUILD_BUG_ON_MSG()
and statically_true().
It has found some 'interesting' code.
David
>
> Signed-off-by: Vincent Mailhol <[email protected]>
> ---
> include/linux/minmax.h | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/include/linux/minmax.h b/include/linux/minmax.h
> index
> 98008dd92153db10c672155bca93201ffabee994..431bf76ac460a11a2e4af23acd90c0d26e99c862
> 100644
> --- a/include/linux/minmax.h
> +++ b/include/linux/minmax.h
> @@ -111,8 +111,7 @@
> __auto_type uval = (val);
> \
> __auto_type ulo = (lo);
> \
> __auto_type uhi = (hi);
> \
> - static_assert(__builtin_choose_expr(__is_constexpr((lo) > (hi)),
> \
> - (lo) <= (hi), true),
> \
> + static_assert(!is_const_false((lo) <= (hi)),
> \
> "clamp() low limit " #lo " greater than high limit " #hi);
> \
> BUILD_BUG_ON_MSG(!__types_ok3(val,lo,hi,uval,ulo,uhi),
> \
> "clamp("#val", "#lo", "#hi") signedness error");
> \
>
> --
> 2.45.2
>
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT,
UK
Registration No: 1397386 (Wales)
