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Subject: Re: Please explain

Author: Steve Maughan

Date: 03:54:10 12/11/01

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Vincent,

>On my paper bitboards should be much faster on K7 as you can
>do BSF/BSR to a 64 bits register without branch mispredictions,
>and i don't see how to do that on the P3.

Interesting.  Can you explain a little more?  Is this Dann Corbit's trick i.e.

function BSF(var i : int64) : integer; register; overload;
asm
  BSF		ECX,DWORD PTR [EAX+04h]
  ADD		ECX,32
  BSF		ECX,DWORD PTR [EAX+00h]
  MOV		EAX,ECX
end;

Or do you mean using MMX?  Are there any code snippets?

Thanks,

Steve



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