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Subject: Re: It seems to me more logical instead of firstone and lastone to use

Author: Matt Taylor

Date: 10:43:26 01/26/03

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On January 26, 2003 at 12:19:55, Antonio Dieguez wrote:

>On January 26, 2003 at 12:00:03, Robert Hyatt wrote:
>
>>On January 26, 2003 at 11:55:27, Antonio Dieguez wrote:
>>
>>>On January 26, 2003 at 10:34:51, Robert Hyatt wrote:
>>>
>>>>Fen starts from the last rank because, by standard, chess boards are displayed
>>>>with white on the bottom.  It is more natural to read left to right, top to
>>>>bottom, which means a8-h8, a7-h7, ..., a1-h1
>>>>
>>>>It was done for simplicity and nothing else.
>>>
>>>Hi, still, I don't know if you don't loop too much, with your magical bitboards,
>>>but with other repr one would like to increment the position when moving forward
>>>with white so it has its simplicity there.
>>
>>you can still do that.  Just let the LSB = a1, rather than the MSB.  Then you
>>can use native BSR/BSF instructions that will return the right number...  Or
>>the LSB could be h1 and go up from there if you want to be able to "visualize"
>>things a bit easier.
>>
>>In Crafty, I have symbolically named each bit with a typedef, so changing this
>>is not all _that_ hard, and I am probably going to do it one day before long
>>simply to make BSF/BSR more useful.
>
>haha. ok then.
>I'm just an iliterate. LSB? BSF/BSR? :) forget what i said if it is unimportant.
>
>best wishes.

LSB - Least Significant Bit
BSF - Bit Scan Forward (x86 instruction)
BSR - Bit Scan Reverse (x86 instruction)

-Matt



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