Package: pari

Version: 2.8.0

Increasing precision for bnfinit() calculation results in an error when retrieving fundamental units that does not occur for default precision.

Increasing the precision further, the error goes away and shows that the default precision calculation was correct.

This only happens on 32 bit version (only tested on Windows 10).

On 64 bit version (tested with 2.8.0 (development 19357-d770f77)), all the precisions tested work consistently without errors.

Below is the output from the 32 bit version.

Regards,

Paul

                                   GP/PARI CALCULATOR Version 2.8.0 (development 19355-c7ae729)
                                    i686 running mingw (ix86/GMP-6.0.0 kernel) 32-bit version
                                     compiled: Aug 26 2016, gcc version 5.4.0 20160609 (GCC)
                                                     threading engine: single
                                          (readline v6.2 enabled, extended help enabled)

                                              Copyright (C) 2000-2016 The PARI Group

PARI/GP is free software, covered by the GNU General Public License, and comes WITHOUT ANY WARRANTY WHATSOEVER.

Type ? for help, \q to quit.
Type ?15 for how to get moral (and possibly technical) support.

parisize = 4000000, primelimit = 500000
? f=x^4-213115048384*x^2+11354436394676863413121
%1 = x^4 - 213115048384*x^2 + 11354436394676863413121
? allocatemem
***   Warning: new stack size = 8000000 (7.629 Mbytes).
? allocatemem
***   Warning: new stack size = 16000000 (15.259 Mbytes).
? nf1=bnfinit(f);
? nf1.fu
%3 = [Mod(1/326431*x^2 - 325624, x^4 - 213115048384*x^2 + 11354436394676863413121), Mod(1/106557197761*x^3 + 1/326431*x^2 - 326433/326431*x - 326432, x^4 - 213115048384*x^2 + 11354436394676863413121), Mod(808/106557197761*x^3 - 263757864/326431*x - 652863, x^4 - 213115048384*x^2 + 11354436394676863413121)]
? \p 50
   realprecision = 57 significant digits (50 digits displayed)
? nf2=bnfinit(f);
? nf2.fu
***   at top-level: nf2.fu
***                     ^--
*** _.fu: missing units in bnf.
***   Break loop: type 'break' to go back to GP prompt
break> break

? \p 100
   realprecision = 105 significant digits (100 digits displayed)
? nf3=bnfinit(f);
? nf3.fu
%6 = [Mod(1/326431*x^2 - 325624, x^4 - 213115048384*x^2 + 11354436394676863413121), Mod(1/106557197761*x^3 + 1/326431*x^2 - 326433/326431*x - 326432, x^4 - 213115048384*x^2 + 11354436394676863413121), Mod(808/106557197761*x^3 - 263757864/326431*x - 652863, x^4 - 213115048384*x^2 + 11354436394676863413121)]
?