Commit Graph

6 Commits

Author SHA1 Message Date
Iker Pedrosa
3b3d3e5cd4 lib: bit_ceil_wrapul(): stop recursion
It should call bit_ceilul() instead of itself.

Fixes: 0712b236c3 ("Add bit manipulation functions")
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2023-02-24 12:44:14 -06:00
Iker Pedrosa
21d88b4525 lib: define ULONG_WIDTH if non-existent
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2023-02-24 12:44:14 -06:00
Alejandro Colomar
03bbe6c418 leading_zerosul(): Fix bug
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-02-01 09:10:34 +01:00
Alejandro Colomar
0712b236c3 Add bit manipulation functions
We do need the unoptimized version of csrand_uniform() for high values
of `n`, since the optimized version depends on having __int128, and it's
not available on several platforms, including ARMv7, IA32, and MK68k.

This reverts commit 848f53c1d3c1362c86d3baab6906e1e4419d2634; however,
I applied some tweaks to the reverted commit.

Reported-by: Adam Sampson <ats@offog.org>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-01-30 18:24:15 +01:00
Alejandro Colomar
848f53c1d3 Revert "Add bit manipulation functions"
Now that we optimized csrand_uniform(), we don't need these functions.

This reverts commit 7c8fe291b1260e127c10562bfd7616961013730f.

Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-01-27 21:48:37 -06:00
Alejandro Colomar
4a56f2baab Add bit manipulation functions
These functions implement bit manipulation APIs, which will be added to
C23, so that in the far future, we will be able to replace our functions
by the standard ones, just by adding the stdc_ prefix, and including
<stdbit.h>.

However, we need to avoid UB for an input of 0, so slightly deviate from
C23, and use a different name (with _wrap) for distunguishing our API
from the standard one.

Cc: Joseph Myers <joseph@codesourcery.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-01-27 21:48:37 -06:00