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    SubjectRe: [PATCH 1/3] X86: Optimise fls(), ffs() and fls64()
    On 04/15/2010 11:48 AM, David Howells wrote:
    > Avi Kivity<> wrote:
    >> Even if Intel processors behave that way, other processors (real and
    >> emulated) use those manuals as a specification. Emulated processors are
    >> unlikely to touch an undefined register, but real processors may.
    >> (qemu tcg appears not to touch the output)
    > Possibly because the AMD64 spec specifies that the destination will be
    > unchanged if the source was 0.

    Likely. But we haven't tested all current and future x86 clones, and
    they may be based off the Intel documentation instead of the AMD

    I have a truly marvellous patch that fixes the bug which this
    signature is too narrow to contain.

     \ /
      Last update: 2010-04-15 10:53    [W:0.021 / U:38.928 seconds]
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