[rc5] Various results, various CPUs

James Johnson plexus at seanet.com
Mon Jul 28 14:47:53 EDT 1997

At 16.19 28/07/97 +0300, you wrote:
>I'd really like to know if the most timecconsuming code fits in the 8K
>cache of a regular Pentium and what is really the operation(s) that uses
>up the most time. I seem to recall reading once that the rotate
>instructions are rather slow in a Pentium, perhaps this could be the
>reason for the advantage of other processors over the Pentium?

Not likely. The x86 arch has the rotate instructions; at most (providing
there are no AGIs) executes in 4 clocks (anywhere from 1 to 4 clk). My
understanding is that most other architectures do not have these
instructions. PPC does however. So with this in mind it is no suprise that
PPC, and x86 architectures are the best for RC5.

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  xor     ax,dx       ;  no try." Yoda
  sub     ax,dx       ;
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