• Linus Torvalds's avatar
    Make ARCH_HAS_FAST_MULTIPLIER a real config variable · 72d93104
    Linus Torvalds authored
    It used to be an ad-hoc hack defined by the x86 version of
    <asm/bitops.h> that enabled a couple of library routines to know whether
    an integer multiply is faster than repeated shifts and additions.
    This just makes it use the real Kconfig system instead, and makes x86
    (which was the only architecture that did this) select the option.
    NOTE! Even for x86, this really is kind of wrong.  If we cared, we would
    probably not enable this for builds optimized for netburst (P4), where
    shifts-and-adds are generally faster than multiplies.  This patch does
    *not* change that kind of logic, though, it is purely a syntactic change
    with no code changes.
    This was triggered by the fact that we have other places that really
    want to know "do I want to expand multiples by constants by hand or
    not", particularly the hash generation code.
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Kconfig 11.7 KB