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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, Richard B. Johnson wrote:

    > > 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.
    >
    > And "m" is presumably described in details elsewhere as the semantics is
    > common for all instructions involving address calculation.

    My documentation says:

    lea reg16, mem
    Available on 8086, 80186, 80286, 80386, 80486
    32-bit-extension available
    Opcode: 8D mod reg r/m

    reg will be the target register (AX .. DI), and mod and r/m will select
    something like a direct address, a register or a combination like
    BP+DI+ofs (I won't copy the table). A multiplier is not mentioned there.
    --
    Microwave: Signal from a friendly micro...
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