Re: Using pari/gp on Android

[Andreas Enge <andreas.enge@inria.fr>]

Hello Дмитрий,

On Mon, Jul 22, 2019 at 03:45:28PM +0300, Дмитрий Рыбас wrote:
> So I tried (and succeded) another way.
> There's Termux app in PlayMarket. It's "prefixed linux environment" for
> android.
> I've managed to compile pari/gp right on device, and it runs just as in any
> other pari/gp in linux, with readline, GMP, read-write to files etc. 
> It's possible to run multiple sessions in Termux, so it's possible to have
> multiple pari/gp instances (I use one for help, and another for scripting).

thanks for sharing this experience with all the details! It looks quite
interesting indeed. Notice that termux is also available via Fdroid; so you
can avoid Google altogether, and if you do not trust the Fdroid binaries,
even easily compile it from source (just as with the PariDroid app).

> Compared to PariDroid, pari/gp runs under Termux a little bit faster (actually,
> some calculations I done about a year before, run significantly faster, but I
> couldn't reproduce them now).

This could be due to (lack of) 64 bit support in PariDroid, which is
cross-compiled on an x86_64 system towards ARM 32 bit, whereas your
hand-compiled binary should have correct 64 bit support. The next PariDroid
release will come with a "fat APK", containing 32 bit and 64 bit PARI
libraries. I did not make extensive tests; whether there is a speed-up will
depend on how much multiprecision computation your problem requires.

Andreas