Re: Faster exponentiation in some extensions of finite fields of small characteristics

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Fri, Jan 15, 2016 at 11:28:20AM +0100, Jean-Pierre Flori wrote:
> Dear all,
> 
> Here is a simplified patch only adding the 4-into-1 stuff.
> It could surely be refactorized as well, but it's simple enough to be included.
> It lacks proper tuning.
> 
> Improvement example:
> * before:
> ? a = ffgen(7^1000,'a)
> time = 32 ms.
> %1 = a
> ? a^(7^1000)
> time = 724 ms.
> %2 = a
> * after:
> ? a = ffgen(7^1000,'a)
> time = 20 ms.
> %1 = a
> ? a^(7^1000)
> time = 368 ms.
> %2 = a
> 
> so a 2x speedup as expected.

Applied thanks! 
I also added the corresponding tuning parameter.

Cheers,
Bill.