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    SubjectRe: 64 bit divide/mod in 2.4.0-test5
    Followup to:  <8mfjbs$5u9$>
    By author: (Linus Torvalds)
    In newsgroup:
    > There's some special-case code in <asm/div64.h>, which is used mainly
    > for printk(), but can be used for other stuff too: a 64-by-64 divide is
    > usually much slower than a 64-by-32 divide which is actually the one
    > that most people are looking for anyway (but gcc isn't clever enough to
    > know this). That can be used if you _really_ think you need the divide.
    > I've yet to see a real reason for it outside the printk() stuff..

    There is also big difference on some architectures between 64/32 = 64
    and 64/32 = 32 (the latter is a single, albeit slow, instruction on
    x86.) I'm rather surprised gcc doesn't handle this -- it seems as an
    obvious optimization.

    Could we get the gcc people to look at this?


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