Re: [vhdl-200x] Modular types

From: <whygee@f-cpu.org>
Date: Wed Jul 09 2014 - 13:08:54 PDT
Le 2014-07-09 21:44, Brian Drummond a écrit :
> On Wed, 2014-06-25 at 14:17 +0000, Martin.J Thompson wrote:
>> So, are there any features you would like which are not mentioned?
>> Constraints which do not make sense?
> 
> I would agree but I would suggest (as Whygee suggested following his
> experiments) adding shift and rotate operators.
> 
> The meaning of these is easy to understand for the modulo-2**n case. 
> but
> may require some thought in the more general case (I would suggest 
> shift
> on a bit position basis, followed by a modulo operation like the and/or
> operations.
> 
> - Brian

Hello,

In a Galois field, shifts are equivalent to multiplies and divides.

They make sense in Z(2^n) and may have applications in other fields
but I still fail to see the need for non-binary fields.
I have not seen anyone here mention their use of modular arithmetic,
beyond the obvious cryptography and ECC fields, which by the way
do not require language support and already deal with binary numbers 
well.

So, beyond the obvious case of binary numbers,
why are we spending time on other bases, since they
don't bring speed or ease advantages ?
CPUs support booleans mod 2^(2^n)) but not mod n^m...

yg

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Received on Wed Jul 9 13:09:07 2014

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