• Alexander van Heukelum's avatar
    x86: merge the simple bitops and move them to bitops.h · 12d9c842
    Alexander van Heukelum authored
    Some of those can be written in such a way that the same
    inline assembly can be used to generate both 32 bit and
    64 bit code.
    
    For ffs and fls, x86_64 unconditionally used the cmov
    instruction and i386 unconditionally used a conditional
    branch over a mov instruction. In the current patch I
    chose to select the version based on the availability
    of the cmov instruction instead. A small detail here is
    that x86_64 did not previously set CONFIG_X86_CMOV=y.
    
    Improved comments for ffs, ffz, fls and variations.
    Signed-off-by: default avatarAlexander van Heukelum <heukelum@fastmail.fm>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    12d9c842
bitops_32.h 1.96 KB