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Subject: Re: A random thought about bitboards

Author: Robert Hyatt

Date: 12:23:35 10/24/01

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On October 24, 2001 at 13:35:48, Tony Werten wrote:

>On October 24, 2001 at 09:40:15, Robert Hyatt wrote:
>
>>On October 24, 2001 at 05:38:21, Ricardo Gibert wrote:
>>
>>>I originally posted this on CTF by mistake. On Tina's suggestion, I've reposted
>>>it here.
>>>
>>>
>>>I know very little about bit boards, but I had random thought about what you
>>>could do with a cpu that has 128 bit words. Does it make any sense to use 128
>>>bits instead of 64 bits in a bitboard approach that is analogous to 0x88? Would
>>>rotated bitboards still be necessary?
>>>
>>>Okay, I know these are random thoughts indeed. So what advantage if any would
>>>128 bits have for bitboards?
>>
>>Rotated bitboards would still be useful.  But now it would take one operation
>>to update two of them at once.  IE normal and rotated 90 in one 128-bit
>>word, the two diagonal rotations in another 128 bit word.  Would work fine.
>>
>>Although 128 bit microprocessors are probably 20 years away or longer...
>
>Why 20 ? The amount of bits seem to have doubled every 10 years until now.
>
>Tony

Demand.  Even supercomputers of today don't use 128 bits.  Such values are
so very big it is not very likely they will be used for quite a while.  IE most
"numbers" simply don't require such large representations, which wastes a lot
of bus bandwidth transferring 128 bit values when the majority are 16 bits or
less...



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