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    SubjectRe: .../asm-i386/bitops.h performance improvements
    On Wed, 15 Jun 2005, Maciej W. Rozycki wrote:

    > On Wed, 15 Jun 2005, Bodo Eggert wrote:
    >
    >> lea is an 8086 instruction. All clones have it in it's basic form. However,
    >> the multiplicator is not documented for i486, therefore it will be a i586
    >> extension.
    >
    > Huh? The SIB byte has been added in the original i386 with 32-bit
    > addressing.
    >
    > Maciej

    Well the __documented__ '486 LEA instruction doesn't
    even allow the double-register indirect. It's just

    LEA r16,m
    LEA r32,m

    ... repeated twice

    Page 26-190, Intel486(tm) Microprocessor Programmer's Reference
    Manual. ISBN 1-55512-195-4. The instruction may have been one
    of those "immature features", read broken.

    Cheers,
    Dick Johnson
    Penguin : Linux version 2.6.11.9 on an i686 machine (5537.79 BogoMips).
    Notice : All mail here is now cached for review by Dictator Bush.
    98.36% of all statistics are fiction.
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