From: Vincent Mailhol > Sent: 02 December 2024 17:33 > > __builtin_choose_expr(__is_constexpr((l) > (h)), (l) > (h), 0) > > is equivalent to: > > is_const_true((l) > (h)) Change it to BUILD_BUG_ON_MSG(statically_true((l) < (h)), "error message") and then fix all the fallout :-) David > > Apply is_const_true() to simplify GENMASK_INPUT_CHECK(). > > Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> > --- > This change passes the unit tests from CONFIG_BITS_TEST, including the > extra negative tests provided under #ifdef TEST_GENMASK_FAILURES [1]. > > [1] commit 6d511020e13d ("lib/test_bits.c: add tests of GENMASK") > Link: https://git.kernel.org/torvalds/c/6d511020e13d > --- > include/linux/bits.h | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/include/linux/bits.h b/include/linux/bits.h > index 60044b6088172b3f26aa3f17cdaede9786863dae..ef0119e6179e1ca95345a3d4d3327ba19633028e 100644 > --- a/include/linux/bits.h > +++ b/include/linux/bits.h > @@ -20,9 +20,8 @@ > */ > #if !defined(__ASSEMBLY__) > #include <linux/build_bug.h> > -#define GENMASK_INPUT_CHECK(h, l) \ > - (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \ > - __is_constexpr((l) > (h)), (l) > (h), 0))) > +#include <linux/compiler.h> > +#define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(is_const_true((l) > (h))) > #else > /* > * BUILD_BUG_ON_ZERO is not available in h files included from asm files, > > -- > 2.45.2 > - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)