Upgrade to PARI 2.9.1

[jdemeyer]

Tarball: http://pari.math.u-bordeaux.fr/pub/pari/unix/pari-2.9.1.tar.gz

Numerous doctests have to be changed, due to different outputs from PARI (in particular the unit group of number fields).

One doctest change is potentially dubious but has been checked by John Cremona:

         It can happen that no points are found if the height bounds
         used in the search are too small (see :trac:`10745`)::
 
             sage: K.<y> = NumberField(x^4 + x^2 - 7)
             sage: E = EllipticCurve(K, [1, 0, 5*y^2 + 16, 0, 0])
             sage: E.gens(lim1=1, lim3=1)
             []
-            sage: E.rank(), E.gens()  # long time (about 3 s)
-            (1, [(9/25*y^2 + 26/25 : -229/125*y^3 - 67/25*y^2 - 731/125*y - 213/25 : 1)])
+            sage: E.rank(), E.gens(lim3=12)  # long time (about 4s)
+            (1,
+             [(369/25*y^3 + 539/25*y^2 + 1178/25*y + 1718/25 : -29038/125*y^3 - 43003/125*y^2 - 92706/125*y - 137286/125 : 1)])

I had to increase the lim3 value for Simon's 2-descent to find a point. The new point differs from the old point by a 3-torsion point and a sign.

CC: @pjbruin @JohnCremona @kedlaya @jpflori

Component: packages: standard

Keywords: atelierpari2017

Author: Jeroen Demeyer

Branch/Commit: 1d577e1

Reviewer: John Cremona, Jean-Pierre Flori, Vincent Delecroix

Issue created by migration from https://trac.sagemath.org/ticket/21756

[jdemeyer]

Dependencies: #21765

[jdemeyer]

Changed dependencies from #21765 to #21703

[jdemeyer]

Branch: u/jdemeyer/upgrade_to_pari_2_8_1

[jdemeyer]

Commit: a7099ae

[jdemeyer]

New commits:

313b785	Interface PARI precision in bits
f80485f	Remove obsolete comment about stack increasing
b70ec86	Add reference to precision guide in PariInstance.__init__
b4bc24f	Merge tag '7.5.beta1' into t/21703/ticket/21703
3db3275	Only use precisions which are in [33,64] mod 64
a7099ae	Improve documentation

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

457bf64

Upgrade to PARI 2.9.0

[sagetrac-git]

Changed commit from a7099ae to 457bf64

[sagetrac-git]

Changed commit from 457bf64 to 0f226f7

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

0f226f7

Upgrade to PARI 2.9.0

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

920252a

Upgrade to PARI 2.9.0

[sagetrac-git]

Changed commit from 0f226f7 to 920252a

[jpflori]

comment:12

CC'ing random number theory people.

Given that the sum of the two result is of 3-torsion, the new point is still a generator, so should we really worry?
@jdemeyer: do you think the precision change is worrying?

[JohnCremona]

comment:13

Nothing to worry about (in answer to the first question). The algorithm is computing E(Q)/2E(Q) anyway.

[jdemeyer]

comment:14

My worry is that PARI 2.8.0 found a point with the default settings of Simon's 2-descent, while PARI 2.9.0 does not find a point (it only finds a point after increasing some bound).

[kiwifb]

comment:15

I am having trouble with the new stackwarn patch and a pristine pari-2.9.0 tarball.

patching file src/gp/gp.c
patching file src/language/init.c
Hunk #1 succeeded at 740 (offset -34 lines).
Hunk #2 succeeded at 755 (offset -34 lines).
Hunk #3 FAILED at 804.
1 out of 3 hunks FAILED -- saving rejects to file src/language/init.c.rej

Am I doing something wrong?

[jdemeyer]

comment:16

The two patches need to be applied in order.

[kiwifb]

comment:17

I see!

[jpflori]

comment:18

Did you ask about the prec issue on pari-devel?

[jdemeyer]

comment:19

Replying to @jpflori:

Did you ask about the prec issue on pari-devel?

No. Do you think that I should? It's not really a PARI issue, but a potential issue with the 2-descent script.

[jpflori]

comment:20

Sure, but Karim or someone else there could be more knowledgeable than us.

[jdemeyer]

comment:35

[comment:25] is an upstream bug :-(

[jdemeyer]

comment:36

It's not an upstream bug, it's fallout from prot_none.patch.

[jdemeyer]

Changed upstream from Reported upstream. No feedback yet. to none

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

99bb049	Upgrade to PARI 2.9.1
5e91b6d	Update prot_none.patch

[sagetrac-git]

Changed commit from 768635d to 5e91b6d

[sagetrac-git]

Changed commit from 5e91b6d to a0feccc

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

a0feccc

Update prot_none.patch

[sagetrac-git]

Changed commit from a0feccc to f7fabb3

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

f7fabb3

Update prot_none.patch

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

d60ae83	Upgrade to PARI 2.9.1
3da9565	Update prot_none.patch

[sagetrac-git]

Changed commit from f7fabb3 to 3da9565

[jdemeyer]

comment:42

This now passes all tests on 32-bit and 64-bit.

[sagetrac-git]

Changed commit from 3da9565 to 1d577e1

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

b1c66bd	Upgrade to PARI 2.9.1
1d577e1	Update prot_none.patch

[videlec]

Changed reviewer from John Cremona, Jean-Pierre Flori to John Cremona, Jean-Pierre Flori, Vincent Delecroix

[videlec]

comment:44

Probably unrelated but I had one doctest failure running all tests in parallel

sage -t src/sage/libs/gap/assigned_names.py  # 1 doctest failed

I am not able to reproduce it.

[videlec]

Changed keywords from none to atelierpari2017

[vbraun]

Changed branch from u/jdemeyer/upgrade_to_pari_2_8_1 to 1d577e1