Bill Allombert on Mon, 09 Feb 2015 23:00:48 +0100

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Re: FlxqM_mul_Kronecker

On Sat, Feb 07, 2015 at 01:22:47PM +0100, Peter Bruin wrote:
> Bonjour,
> Here is a patch to add a new (private) function FlxqM_mul_Kronecker that
> I have been working on since the Atelier PARI/GP in January.  It uses
> Kronecker substitution to multiply matrices over non-prime finite fields
> of small characteristics.  Over the range of matrices I tested it on, it
> is on average 60%-80% faster than the existing FlxqM_mul; for some
> examples, the speedup is up to 4-5 times.

I read your patch.

I think the function FlxM_to_ZM and ZM_to_FlxqM should be renamed
to something more awkward, maybe FlxM_pack_ZM/ZM_pack_FlxqM

The function zx_to_int* should also be renamed. zx denotes polynomials with small
signed coefficient. Maybe we should add pack/unpack in the name since the 
functions are only wrapper for use as (*pack) or (*unpack).

In FlxqM_mul_Kronecker, maybe a switch(l-2) would be better.