Code coverage tests

This page documents the degree to which the PARI/GP source code is tested by our public test suite, distributed with the source distribution in directory src/test/. This is measured by the gcov utility; we then process gcov output using the lcov frond-end.

We test a few variants depending on Configure flags on the pari.math.u-bordeaux.fr machine (x86_64 architecture), and agregate them in the final report:

The target is to exceed 90% coverage for all mathematical modules (given that branches depending on DEBUGLEVEL or DEBUGMEM are not covered). This script is run to produce the results below.

LCOV - code coverage report
Current view: top level - modules - genus2red.c (source / functions) Hit Total Coverage
Test: PARI/GP v2.18.1 lcov report (development 29950-285c5b69ed) Lines: 1411 1557 90.6 %
Date: 2025-02-05 09:09:51 Functions: 60 60 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /* Copyright (C) 2000  The PARI group.
       2             : 
       3             : This file is part of the PARI/GP package.
       4             : 
       5             : PARI/GP is free software; you can redistribute it and/or modify it under the
       6             : terms of the GNU General Public License as published by the Free Software
       7             : Foundation; either version 2 of the License, or (at your option) any later
       8             : version. It is distributed in the hope that it will be useful, but WITHOUT
       9             : ANY WARRANTY WHATSOEVER.
      10             : 
      11             : Check the License for details. You should have received a copy of it, along
      12             : with the package; see the file 'COPYING'. If not, write to the Free Software
      13             : Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
      14             : #include "pari.h"
      15             : #include "paripriv.h"
      16             : 
      17             : #define DEBUGLEVEL DEBUGLEVEL_genus2red
      18             : 
      19             : /* extract coefficients of a polynomial a0 X^6 + ... + a6, of degree <= 6 */
      20             : static void
      21        2702 : RgX_to_06(GEN q, GEN *a0, GEN *a1, GEN *a2, GEN *a3, GEN *a4, GEN *a5, GEN *a6)
      22             : {
      23        2702 :   *a0 = gen_0;
      24        2702 :   *a1 = gen_0;
      25        2702 :   *a2 = gen_0;
      26        2702 :   *a3 = gen_0;
      27        2702 :   *a4 = gen_0;
      28        2702 :   *a5 = gen_0;
      29        2702 :   *a6 = gen_0;
      30        2702 :   switch(degpol(q))
      31             :   {
      32        1918 :     case 6: *a0 = gel(q,8); /*fall through*/
      33        2702 :     case 5: *a1 = gel(q,7); /*fall through*/
      34        2702 :     case 4: *a2 = gel(q,6); /*fall through*/
      35        2702 :     case 3: *a3 = gel(q,5); /*fall through*/
      36        2702 :     case 2: *a4 = gel(q,4); /*fall through*/
      37        2702 :     case 1: *a5 = gel(q,3); /*fall through*/
      38        2702 :     case 0: *a6 = gel(q,2); /*fall through*/
      39             :   }
      40        2702 : }
      41             : 
      42             : /********************************************************************/
      43             : /**                                                                **/
      44             : /**                       IGUSA INVARIANTS                         **/
      45             : /**                       (GP2C-generated)                         **/
      46             : /**                                                                **/
      47             : /********************************************************************/
      48             : /*
      49             : j2(a0,a1,a2,a3,a4,a5,a6) = (-120*a0*a6+20*a1*a5-8*a2*a4+3*a3^2) / 4;
      50             : */
      51             : static GEN
      52        2345 : igusaj2(GEN a0, GEN a1, GEN a2, GEN a3, GEN a4, GEN a5, GEN a6)
      53             : {
      54        2345 :   pari_sp av = avma;
      55        2345 :   return gerepileupto(av, gmul2n(gadd(gsub(gadd(gmul(gmulsg(-120, a0), a6), gmul(gmulsg(20, a1), a5)), gmul(gmulsg(8, a2), a4)), gmulsg(3, gsqr(a3))), -2));
      56             : }
      57             : 
      58             : /*
      59             : j4(a0,a1,a2,a3,a4,a5,a6) = (240*(a0*a3*a4*a5+a1*a2*a3*a6)-400*(a0*a2*a5^2+a1^2*a4*a6)-64*(a0*a4^3+a2^3*a6)+16*(a1*a3*a4^2+a2^2*a3*a5)-672*a0*a3^2*a6+240*a1^2*a5^2-112*a1*a2*a4*a5-8*a1*a3^2*a5+16*a2^2*a4^2-16*a2*a3^2*a4+3*a3^4+2640*a0^2*a6^2-880*a0*a1*a5*a6+1312*a0*a2*a4*a6) / 2^7
      60             : */
      61             : static GEN
      62        2345 : igusaj4(GEN a0, GEN a1, GEN a2, GEN a3, GEN a4, GEN a5, GEN a6)
      63             : {
      64        2345 :   pari_sp av = avma;
      65        2345 :   return gerepileupto(av,
      66             : gmul2n(gadd(gsub(gadd(gadd(gsub(gadd(gsub(gsub(gadd(gsub(gadd(gsub(gsub(gmulsg(240,
      67             : gadd(gmul(gmul(gmul(a0, a3), a4), a5), gmul(gmul(gmul(a1, a2), a3), a6))),
      68             : gmulsg(400, gadd(gmul(gmul(a0, a2), gsqr(a5)), gmul(gmul(gsqr(a1), a4), a6)))),
      69             : gmulsg(64, gadd(gmul(a0, gpowgs(a4, 3)), gmul(gpowgs(a2, 3), a6)))), gmulsg(16,
      70             : gadd(gmul(gmul(a1, a3), gsqr(a4)), gmul(gmul(gsqr(a2), a3), a5)))),
      71             : gmul(gmul(gmulsg(672, a0), gsqr(a3)), a6)), gmul(gmulsg(240, gsqr(a1)),
      72             : gsqr(a5))), gmul(gmul(gmul(gmulsg(112, a1), a2), a4), a5)), gmul(gmul(gmulsg(8,
      73             : a1), gsqr(a3)), a5)), gmul(gmulsg(16, gsqr(a2)), gsqr(a4))),
      74             : gmul(gmul(gmulsg(16, a2), gsqr(a3)), a4)), gmulsg(3, gpowgs(a3, 4))),
      75             : gmul(gmulsg(2640, gsqr(a0)), gsqr(a6))), gmul(gmul(gmul(gmulsg(880, a0), a1),
      76             : a5), a6)), gmul(gmul(gmul(gmulsg(1312, a0), a2), a4), a6)), -7));
      77             : }
      78             : 
      79             : /*
      80             : j6(a0,a1,a2,a3,a4,a5,a6) = (1600*(a0^2*a4^2*a5^2+a1^2*a2^2*a6^2)+1600*(a0*a1*a2*a5^3+a1^3*a4*a5*a6)+640*(a0*a1*a3*a4*a5^2+a1^2*a2*a3*a5*a6)-4000*(a0^2*a3*a5^3+a1^3*a3*a6^2)-384*(a0*a1*a4^3*a5+a1*a2^3*a5*a6)-640*(a0*a2^2*a4*a5^2+a1^2*a2*a4^2*a6)+80*(a0*a2*a3^2*a5^2+a1^2*a3^2*a4*a6)+192*(a0*a2*a3*a4^2*a5+a1*a2^2*a3*a4*a6)-48*(a0*a3^3*a4*a5+a1*a2*a3^3*a6)-224*(a1^2*a3*a4^2*a5+a1*a2^2*a3*a5^2)+64*(a1^2*a4^4+a2^4*a5^2)-64*(a1*a2*a3*a4^3+a2^3*a3*a4*a5)+16*(a1*a3^3*a4^2+a2^2*a3^3*a5)-4096*(a0^2*a4^3*a6+a0*a2^3*a6^2)+6400*(a0^2*a2*a5^2*a6+a0*a1^2*a4*a6^2)+10560*(a0^2*a3*a4*a5*a6+a0*a1*a2*a3*a6^2)+2624*(a0*a1*a3*a4^2*a6+a0*a2^2*a3*a5*a6)-4432*a0*a1*a3^2*a5*a6-8*a2*a3^4*a4+a3^6-320*a1^3*a5^3+64*a1^2*a2*a4*a5^2+176*a1^2*a3^2*a5^2+128*a1*a2^2*a4^2*a5+112*a1*a2*a3^2*a4*a5-28*a1*a3^4*a5+16*a2^2*a3^2*a4^2+5120*a0^3*a6^3-2544*a0^2*a3^2*a6^2+312*a0*a3^4*a6-14336*a0^2*a2*a4*a6^2+1024*a0*a2^2*a4^2*a6-2560*a0^2*a1*a5*a6^2-2240*a0*a1^2*a5^2*a6-6528*a0*a1*a2*a4*a5*a6-1568*a0*a2*a3^2*a4*a6) / 2^10
      81             : */
      82             : static GEN
      83        2345 : igusaj6(GEN a0, GEN a1, GEN a2, GEN a3, GEN a4, GEN a5, GEN a6)
      84             : {
      85        2345 :   pari_sp av = avma;
      86        2345 :   return gerepileupto(av,
      87             : gmul2n(gsub(gsub(gsub(gsub(gadd(gsub(gadd(gsub(gadd(gadd(gsub(gadd(gadd(gadd(gadd(gsub(gadd(gsub(gsub(gadd(gadd(gadd(gsub(gadd(gsub(gadd(gsub(gsub(gadd(gadd(gsub(gsub(gsub(gadd(gadd(gmulsg(1600,
      88             : gadd(gmul(gmul(gsqr(a0), gsqr(a4)), gsqr(a5)), gmul(gmul(gsqr(a1), gsqr(a2)),
      89             : gsqr(a6)))), gmulsg(1600, gadd(gmul(gmul(gmul(a0, a1), a2), gpowgs(a5, 3)),
      90             : gmul(gmul(gmul(gpowgs(a1, 3), a4), a5), a6)))), gmulsg(640,
      91             : gadd(gmul(gmul(gmul(gmul(a0, a1), a3), a4), gsqr(a5)),
      92             : gmul(gmul(gmul(gmul(gsqr(a1), a2), a3), a5), a6)))), gmulsg(4000,
      93             : gadd(gmul(gmul(gsqr(a0), a3), gpowgs(a5, 3)), gmul(gmul(gpowgs(a1, 3), a3),
      94             : gsqr(a6))))), gmulsg(384, gadd(gmul(gmul(gmul(a0, a1), gpowgs(a4, 3)), a5),
      95             : gmul(gmul(gmul(a1, gpowgs(a2, 3)), a5), a6)))), gmulsg(640,
      96             : gadd(gmul(gmul(gmul(a0, gsqr(a2)), a4), gsqr(a5)), gmul(gmul(gmul(gsqr(a1),
      97             : a2), gsqr(a4)), a6)))), gmulsg(80, gadd(gmul(gmul(gmul(a0, a2), gsqr(a3)),
      98             : gsqr(a5)), gmul(gmul(gmul(gsqr(a1), gsqr(a3)), a4), a6)))), gmulsg(192,
      99             : gadd(gmul(gmul(gmul(gmul(a0, a2), a3), gsqr(a4)), a5), gmul(gmul(gmul(gmul(a1,
     100             : gsqr(a2)), a3), a4), a6)))), gmulsg(48, gadd(gmul(gmul(gmul(a0, gpowgs(a3, 3)),
     101             : a4), a5), gmul(gmul(gmul(a1, a2), gpowgs(a3, 3)), a6)))), gmulsg(224,
     102             : gadd(gmul(gmul(gmul(gsqr(a1), a3), gsqr(a4)), a5), gmul(gmul(gmul(a1,
     103             : gsqr(a2)), a3), gsqr(a5))))), gmulsg(64, gadd(gmul(gsqr(a1), gpowgs(a4, 4)),
     104             : gmul(gpowgs(a2, 4), gsqr(a5))))), gmulsg(64, gadd(gmul(gmul(gmul(a1, a2), a3),
     105             : gpowgs(a4, 3)), gmul(gmul(gmul(gpowgs(a2, 3), a3), a4), a5)))), gmulsg(16,
     106             : gadd(gmul(gmul(a1, gpowgs(a3, 3)), gsqr(a4)), gmul(gmul(gsqr(a2), gpowgs(a3,
     107             : 3)), a5)))), gmulsg(4096, gadd(gmul(gmul(gsqr(a0), gpowgs(a4, 3)), a6),
     108             : gmul(gmul(a0, gpowgs(a2, 3)), gsqr(a6))))), gmulsg(6400,
     109             : gadd(gmul(gmul(gmul(gsqr(a0), a2), gsqr(a5)), a6), gmul(gmul(gmul(a0,
     110             : gsqr(a1)), a4), gsqr(a6))))), gmulsg(10560, gadd(gmul(gmul(gmul(gmul(gsqr(a0),
     111             : a3), a4), a5), a6), gmul(gmul(gmul(gmul(a0, a1), a2), a3), gsqr(a6))))),
     112             : gmulsg(2624, gadd(gmul(gmul(gmul(gmul(a0, a1), a3), gsqr(a4)), a6),
     113             : gmul(gmul(gmul(gmul(a0, gsqr(a2)), a3), a5), a6)))),
     114             : gmul(gmul(gmul(gmul(gmulsg(4432, a0), a1), gsqr(a3)), a5), a6)),
     115             : gmul(gmul(gmulsg(8, a2), gpowgs(a3, 4)), a4)), gpowgs(a3, 6)), gmul(gmulsg(320,
     116             : gpowgs(a1, 3)), gpowgs(a5, 3))), gmul(gmul(gmul(gmulsg(64, gsqr(a1)), a2), a4),
     117             : gsqr(a5))), gmul(gmul(gmulsg(176, gsqr(a1)), gsqr(a3)), gsqr(a5))),
     118             : gmul(gmul(gmul(gmulsg(128, a1), gsqr(a2)), gsqr(a4)), a5)),
     119             : gmul(gmul(gmul(gmul(gmulsg(112, a1), a2), gsqr(a3)), a4), a5)),
     120             : gmul(gmul(gmulsg(28, a1), gpowgs(a3, 4)), a5)), gmul(gmul(gmulsg(16, gsqr(a2)),
     121             : gsqr(a3)), gsqr(a4))), gmul(gmulsg(5120, gpowgs(a0, 3)), gpowgs(a6, 3))),
     122             : gmul(gmul(gmulsg(2544, gsqr(a0)), gsqr(a3)), gsqr(a6))), gmul(gmul(gmulsg(312,
     123             : a0), gpowgs(a3, 4)), a6)), gmul(gmul(gmul(gmulsg(14336, gsqr(a0)), a2), a4),
     124             : gsqr(a6))), gmul(gmul(gmul(gmulsg(1024, a0), gsqr(a2)), gsqr(a4)), a6)),
     125             : gmul(gmul(gmul(gmulsg(2560, gsqr(a0)), a1), a5), gsqr(a6))),
     126             : gmul(gmul(gmul(gmulsg(2240, a0), gsqr(a1)), gsqr(a5)), a6)),
     127             : gmul(gmul(gmul(gmul(gmul(gmulsg(6528, a0), a1), a2), a4), a5), a6)),
     128             : gmul(gmul(gmul(gmul(gmulsg(1568, a0), a2), gsqr(a3)), a4), a6)), -10));
     129             : }
     130             : 
     131             : static GEN
     132          42 : igusaj8_fromj246(GEN j2, GEN j4, GEN j6)
     133          42 : { return gmul2n(gsub(gmul(j2,j6), gsqr(j4)), -2); }
     134             : 
     135             : static GEN
     136          21 : igusaj8(GEN a0, GEN a1, GEN a2, GEN a3, GEN a4, GEN a5, GEN a6)
     137             : {
     138          21 :   pari_sp av = avma;
     139          21 :   GEN j2 = igusaj2(a0,a1,a2,a3,a4,a5,a6);
     140          21 :   GEN j4 = igusaj4(a0,a1,a2,a3,a4,a5,a6);
     141          21 :   GEN j6 = igusaj6(a0,a1,a2,a3,a4,a5,a6);
     142          21 :   return gerepileupto(av, igusaj8_fromj246(j2,j4,j6));
     143             : }
     144             : 
     145             : static GEN
     146          42 : igusaj10(GEN a0, GEN a1, GEN a2, GEN a3, GEN a4, GEN a5, GEN a6)
     147             : {
     148          42 :   pari_sp av = avma;
     149          42 :   GEN polr = mkpoln(7, a0, a1, a2, a3, a4, a5, a6);
     150          42 :   GEN disc = RgX_disc(polr);
     151          42 :   GEN j10 = degpol(polr) < 6? gmul(gsqr(a1), disc): disc;
     152          42 :   return gerepileupto(av, gmul2n(j10, -12));
     153             : }
     154             : 
     155             : static GEN
     156          21 : igusaall(GEN a0, GEN a1, GEN a2, GEN a3, GEN a4, GEN a5, GEN a6)
     157             : {
     158          21 :   GEN j2, j4, j6, V = cgetg(6,t_VEC);
     159             :   pari_sp av;
     160          21 :   gel(V,1) = j2 = igusaj2(a0,a1,a2,a3,a4,a5,a6);
     161          21 :   gel(V,2) = j4 = igusaj4(a0,a1,a2,a3,a4,a5,a6);
     162          21 :   gel(V,3) = j6 = igusaj6(a0,a1,a2,a3,a4,a5,a6);
     163          21 :   av = avma;
     164          21 :   gel(V,4) = gerepileupto(av, igusaj8_fromj246(j2, j4, j6));
     165          21 :   gel(V,5) = igusaj10(a0,a1,a2,a3,a4,a5,a6);
     166          21 :   return V;
     167             : }
     168             : 
     169             : GEN
     170         126 : genus2igusa(GEN P, long n)
     171             : {
     172         126 :   pari_sp av = avma;
     173             :   GEN a0, a1, a2, a3, a4, a5, a6, r;
     174         126 :   if (typ(P) == t_VEC && lg(P) == 3)
     175          42 :     P = gadd(gmul2n(gel(P,1), 2), gsqr(gel(P,2)));
     176             :   else
     177          84 :     P = gmul2n(P, 2);
     178         126 :   if (typ(P)!=t_POL || degpol(P)> 6) pari_err_TYPE("genus2igusa",P);
     179         126 :   RgX_to_06(P, &a0,&a1,&a2,&a3,&a4,&a5,&a6);
     180         126 :   switch(n)
     181             :   {
     182          21 :     case 0: r = igusaall(a0,a1,a2,a3,a4,a5,a6); break;
     183          21 :     case 2: r = igusaj2(a0,a1,a2,a3,a4,a5,a6); break;
     184          21 :     case 4: r = igusaj4(a0,a1,a2,a3,a4,a5,a6); break;
     185          21 :     case 6: r = igusaj6(a0,a1,a2,a3,a4,a5,a6); break;
     186          21 :     case 8: r = igusaj8(a0,a1,a2,a3,a4,a5,a6); break;
     187          21 :     case 10:r = igusaj10(a0,a1,a2,a3,a4,a5,a6); break;
     188           0 :     default:
     189           0 :       pari_err_FLAG("genus2igusa");
     190             :       return NULL; /* LCOV_EXCL_LINE */
     191             :   }
     192         126 :   return gerepileupto(av, r);
     193             : }
     194             : 
     195             : /********************************************************************/
     196             : /**                                                                **/
     197             : /**   A REDUCTION ALGORITHM "A LA TATE" FOR CURVES OF GENUS 2      **/
     198             : /**                                                                **/
     199             : /********************************************************************/
     200             : /* Based on genus2reduction-0.3, http://www.math.u-bordeaux.fr/~liu/G2R/
     201             :  * by Qing Liu <liu@math.u-bordeaux.fr>
     202             :  * and Henri Cohen <cohen@math.u-bordeaux.fr>
     203             : 
     204             :  * Qing Liu: Modeles minimaux des courbes de genre deux
     205             :  * J. fuer die Reine und Angew. Math., 453 (1994), 137-164.
     206             :  * http://www.math.u-bordeaux.fr/~liu/articles/modregE.ps */
     207             : 
     208             : /* some auxiliary polynomials, gp2c-generated */
     209             : 
     210             : /*
     211             : apol2(a0,a1,a2) = -5*a1^2+12*a0*a2;
     212             : */
     213             : static GEN
     214        2282 : apol2(GEN a0, GEN a1, GEN a2)
     215             : {
     216        2282 :   return gadd(gmulsg(-5, gsqr(a1)), gmul(gmulsg(12, a0), a2));
     217             : }
     218             : 
     219             : /*
     220             : apol3(a0,a1,a2,a3) = 5*a1^3+9*a0*(-2*a1*a2+3*a0*a3);
     221             : */
     222             : static GEN
     223        2282 : apol3(GEN a0, GEN a1, GEN a2, GEN a3)
     224             : {
     225        2282 :   return gadd(gmulsg(5, gpowgs(a1, 3)), gmul(gmulsg(9, a0), gadd(gmul(gmulsg(-2, a1), a2), gmul(gmulsg(3, a0), a3))));
     226             : }
     227             : 
     228             : /*
     229             : apol5(a0,a1,a2,a3,a4,a5) = a1^5+3*a0*(-2*a1^3*a2+9*a0*a1^2*a3-36*a0^2*a1*a4+108*a0^3*a5);
     230             : */
     231             : static GEN
     232        2282 : apol5(GEN a0, GEN a1, GEN a2, GEN a3, GEN a4, GEN a5)
     233             : {
     234        2282 :   return gadd(gpowgs(a1, 5), gmul(gmulsg(3, a0), gadd(gsub(gadd(gmul(gmulsg(-2, gpowgs(a1, 3)), a2), gmul(gmul(gmulsg(9, a0), gsqr(a1)), a3)), gmul(gmul(gmulsg(36, gsqr(a0)), a1), a4)), gmul(gmulsg(108, gpowgs(a0, 3)), a5))));
     235             : }
     236             : 
     237             : /*
     238             : bpol2(a0,a1,a2,a3,a4) = 2*a2^2-5*a1*a3+10*a0*a4;
     239             : */
     240             : static GEN
     241        2282 : bpol2(GEN a0, GEN a1, GEN a2, GEN a3, GEN a4)
     242             : {
     243        2282 :   return gadd(gsub(gmulsg(2, gsqr(a2)), gmul(gmulsg(5, a1), a3)), gmul(gmulsg(10, a0), a4));
     244             : }
     245             : 
     246             : static const long VERYBIG = (1L<<20);
     247             : static long
     248       38451 : myval(GEN x, GEN p) { return signe(x)? Z_pval(x,p): VERYBIG; }
     249             : static long
     250        2982 : my3val(GEN x) { return signe(x)? Z_lval(x,3): VERYBIG; }
     251             : /* b in Z[i], return v_3(b) */
     252             : static long
     253        1491 : myval_zi(GEN b) { return minss(my3val(real_i(b)), my3val(imag_i(b))); }
     254             : /* b in Z[i, Y]/(Y^2-3), return v_Y(b) */
     255             : static long
     256         672 : myval_zi2(GEN b)
     257             : {
     258             :   long v0, v1;
     259         672 :   b = lift_shallow(b);
     260         672 :   v0 = myval_zi(RgX_coeff(b,0));
     261         672 :   v1 = myval_zi(RgX_coeff(b,1));
     262         672 :   return minss(2*v0, 2*v1+1);
     263             : }
     264             : 
     265             : /* min(a,b,c) */
     266             : static long
     267        3129 : min3(long a, long b, long c)
     268             : {
     269        3129 :   long m = a;
     270        3129 :   if (b < m) m = b;
     271        3129 :   if (c < m) m = c;
     272        3129 :   return m;
     273             : }
     274             : 
     275             : /* Vector of p-adic factors (over Q_p) to accuracy r of pol. */
     276             : static GEN
     277         175 : padicfactors(GEN pol, GEN p, long r) { return gel(factorpadic(pol,p,r),1); }
     278             : 
     279             : /* x(1/t)*t^6, deg x <= 6 */
     280             : static GEN
     281         392 : RgX_recip6(GEN x)
     282             : {
     283         392 :   long lx = lg(x), i, j;
     284         392 :   GEN y = cgetg(9, t_POL);
     285         392 :   y[1] = x[1];
     286        2940 :   for (i=8,j=2; j < lx; i--,j++) gel(y,i) = gel(x,j);
     287         588 :   for (       ; j <  9; i--,j++) gel(y,i) = gen_0;
     288         392 :   return normalizepol_lg(y, 9);
     289             : }
     290             : /* extract coefficients a0,...a3 of a polynomial a0 X^6 + ... + a6 */
     291             : static void
     292        2282 : RgX_to_03(GEN q, GEN *a0, GEN *a1, GEN *a2, GEN *a3)
     293             : {
     294        2282 :   *a0 = gen_0;
     295        2282 :   *a1 = gen_0;
     296        2282 :   *a2 = gen_0;
     297        2282 :   *a3 = gen_0;
     298        2282 :   switch(degpol(q))
     299             :   {
     300        1491 :     case 6: *a0 = gel(q,8); /*fall through*/
     301        2282 :     case 5: *a1 = gel(q,7); /*fall through*/
     302        2282 :     case 4: *a2 = gel(q,6); /*fall through*/
     303        2282 :     case 3: *a3 = gel(q,5); /*fall through*/
     304             :   }
     305        2282 : }
     306             : 
     307             : /* deg(H mod p) = 3, return v_p( disc(corresponding p-adic factor) ) */
     308             : static long
     309          21 : discpart(GEN H, GEN p, long prec)
     310             : {
     311             :   GEN list, prod, dis;
     312             :   long i, j;
     313             : 
     314          21 :   if (degpol(FpX_red(H,p)) != 3)
     315             :     pari_err_BUG("discpart [must not reach]"); /* LCOV_EXCL_LINE */
     316          21 :   list = padicfactors(H,p,prec);
     317          21 :   prod = pol_1(varn(H));
     318          84 :   for(i = 1; i < lg(list); i++)
     319             :   {
     320          63 :     GEN t = gel(list,i);
     321         126 :     for(j = 3; j < lg(t); j++) /* include if nonconstant mod p */
     322         105 :       if (!valp(gel(t,j))) { prod = RgX_mul(prod,t); break; }
     323             :   }
     324          21 :   if (degpol(prod) != 3) pari_err_BUG("discpart [prod degree]");
     325          21 :   dis = RgX_disc(prod);
     326          21 :   return gequal0(dis)? prec+1: valp(dis);
     327             : }
     328             : 
     329             : /* B = b0 X^6 + ... + b6 a ZX, 0 <= j <= 3.
     330             :  * Let theta_j(H) := min { v_p(b_i) / (i - j), j < i <= 6 } >= 0.
     331             :  * Return 60 theta \in Z */
     332             : static long
     333        2842 : theta_j(GEN B, GEN p, long j)
     334             : {
     335        2842 :   long i, t = VERYBIG;
     336       13916 :   for(i = 1+j; i <= 6; i++)
     337       11074 :     t = minss(t, myval(RgX_coeff(B,6-i), p) * (60 / (i-j)));
     338        2842 :   return t;
     339             : }
     340             : /* compute 6 * theta_3 for B in Z[i][X], p = 3 */
     341             : static long
     342          28 : theta_3_zi(GEN B)
     343             : {
     344          28 :   long v2 = myval_zi(RgX_coeff(B,2));
     345          28 :   long v1 = myval_zi(RgX_coeff(B,1));
     346          28 :   long v0 = myval_zi(RgX_coeff(B,0));
     347          28 :   return min3(6*v2, 3*v1, 2*v0);
     348             : }
     349             : /* compute 6 * theta_3 for B in (Z[i,Y]/(Y^2-3))[X], p = 3 */
     350             : static long
     351          84 : theta_3_zi2(GEN B)
     352             : {
     353          84 :   long v2 = myval_zi2(RgX_coeff(B,2));
     354          84 :   long v1 = myval_zi2(RgX_coeff(B,1));
     355          84 :   long v0 = myval_zi2(RgX_coeff(B,0));
     356          84 :   return min3(6*v2, 3*v1, 2*v0);
     357             : }
     358             : 
     359             : /* Set maxord to the maximal multiplicity of a factor. If there is at least
     360             :  * a triple root (=> maxord >= 3) return it, else return NULL */
     361             : static GEN
     362         987 : factmz(GEN Q, GEN p, long *maxord)
     363             : {
     364         987 :   GEN z = FpX_factor_squarefree(Q, p);
     365         987 :   long m = lg(z)-1; /* maximal multiplicity */
     366         987 :   *maxord = m;
     367         987 :   return (m >= 3)? FpX_oneroot(gel(z,m), p): NULL;
     368             : }
     369             : static long
     370        2695 : get_lambda(GEN H, GEN p)
     371             : {
     372        2695 :   if (!dvdii(RgX_coeff(H,3), p)) return 3;
     373        1197 :   if (!dvdii(RgX_coeff(H,4), p)) return 2;
     374         931 :   if (!dvdii(RgX_coeff(H,5), p)) return 1;
     375         721 :   if (!dvdii(RgX_coeff(H,6), p)) return 0;
     376         112 :   return -1;
     377             : }
     378             : 
     379             : /* H integral ZX of degree 5 or 6, p > 2. Modify until
     380             :  *   y^2 = p^alpha H is minimal over Z_p, alpha = 0,1
     381             :  * Return [H,lambda,60*theta,alpha,quad,beta], where
     382             :  *   - quad = 1 if H has a root of order 3 in F_p^2 \ F_p, 0 otherwise
     383             :  *   - 0 <= lambda <= 3, index of a coefficient with valuation 0
     384             :  *   - theta = theta_j(H(x + r), p, lambda), 60*theta in Z, where r is a root
     385             :  *   of H mod p
     386             :  *   - beta >= -1 s.t. H = p^n H0(r + p^beta * X) for some n, r in Z, where
     387             :  *   H0 is the initial H or polrecip(H) */
     388             : static GEN
     389        2583 : polymini(GEN H, GEN p)
     390             : {
     391        2583 :   long t60, alpha, lambda, quad = 0, beta = 0;
     392             :   GEN Hp;
     393             : 
     394        2583 :   alpha = ZX_pvalrem(H, p, &H) & 1;
     395        2583 :   lambda = get_lambda(H, p);
     396        2583 :   if (lambda < 0) { H = RgX_recip6(H); lambda = get_lambda(H, p); }
     397           0 :   for(;;)
     398             :   {
     399             :     for(;;)
     400         259 :     { /* lambda <= 3, t60 = 60*theta */
     401             :       GEN rac;
     402             :       long e, maxord;
     403        2842 :       t60 = theta_j(H,p,lambda); e = t60 / 60;
     404        2842 :       if (e)
     405             :       {
     406        1309 :         GEN pe = powiu(p,e);
     407             :         /* H <- H(p^e X) / p^(e(6-lambda)) */
     408        1309 :         H = ZX_unscale_divpow(H, pe, 6-lambda);
     409        1309 :         alpha = (alpha + lambda*e)&1;
     410        1309 :         beta += e;
     411        1309 :         t60 -= 60*e;
     412             :       }
     413             :       /* 0 <= t < 60 */
     414        2842 :       Hp = FpX_red(H, p); if (t60) break;
     415             : 
     416         973 :       rac = factmz(Hp,p, &maxord);
     417         973 :       if (maxord <= 2)
     418             :       {
     419         693 :         if (degpol(Hp) <= 3) break;
     420         175 :         goto end;
     421             :       }
     422             :       /* maxord >= 3 */
     423         280 :       if (!rac) { quad = 1; goto end; }
     424         259 :       if (signe(rac)) H = ZX_translate(H, rac);
     425         259 :       lambda = 6 - maxord;
     426             :     }
     427        2408 :     if (lambda <= 2)
     428             :     {
     429        1043 :       if (myval(RgX_coeff(H,2),p) > 1-alpha &&
     430         875 :           myval(RgX_coeff(H,1),p) > 2-alpha &&
     431         693 :           myval(RgX_coeff(H,0),p) > 3-alpha)
     432             :       {
     433           0 :         H = ZX_unscale(H, p);
     434           0 :         if (alpha) H = ZX_Z_mul(H, p);
     435           0 :         return polymini(H, p);
     436             :       }
     437        1043 :       break;
     438             :     }
     439             :     /* lambda = 3 */
     440        1365 :     if (alpha == 0) break;
     441         630 :     if (degpol(Hp) == 3)
     442             :     {
     443        1127 :       if (myval(RgX_coeff(H,6),p) >= 3 &&
     444         560 :           myval(RgX_coeff(H,5),p) >= 2)
     445             :       { /* too close to root [Kodaira symbol for y^2 = p^alpha*H not
     446             :            implemented when alpha = 1]: go back one step */
     447         560 :         H = ZX_rescale(H, p); /* H(x/p)p^(deg H) */
     448         560 :         H = ZX_Z_divexact(H, powiu(p, degpol(H)-3)); /* H(x/p)p^3 */
     449         560 :         t60 += 60; alpha = 0; beta--;
     450             :       }
     451         567 :       break;
     452             :     }
     453          63 :     if (degpol(Hp) != 6) break;
     454          14 :     if (t60)
     455             :     {
     456             :       long m, maxord;
     457          14 :       GEN v, T, rac = factmz(RgX_mulXn(Hp, -3), p, &maxord);
     458          28 :       if (maxord <= 2) break;
     459          14 :       T = ZX_affine(H, p, rac); /* H(rac + px) */
     460          14 :       if (ZX_pval(T,p) < 3) break;
     461             : 
     462           0 :       H = ZX_Z_divexact(T, powiu(p,3));
     463           0 :       alpha = 0; beta++;
     464           0 :       v = FpX_factor_squarefree(FpX_red(H,p), p);
     465           0 :       m = lg(v)-1; /* maximal multiplicity */
     466           0 :       if (m > 1)
     467             :       {
     468           0 :         rac = FpX_oneroot(gel(v,m), p); /* v[m] is linear */
     469           0 :         H = ZX_translate(H,rac);
     470           0 :         t60 = theta_j(H,p,3);
     471           0 :         if (t60 < 60) break;
     472             :       }
     473             :     }
     474             :   }
     475        2583 : end:
     476        2583 :   return mkvec2(H, mkvecsmall5(lambda,t60,alpha,quad,beta));
     477             : }
     478             : 
     479             : /* a in Q[i], return a^3 mod 3 */
     480             : static GEN
     481          14 : zi_pow3mod(GEN a)
     482             : {
     483             :   GEN x, y;
     484          14 :   if (typ(a) != t_COMPLEX) return gmodgs(a,3);
     485           7 :   x = gmodgs(gel(a,1), 3);
     486           7 :   y = gmodgs(gel(a,2), 3);
     487           7 :   return mkcomplex(x, negi(y));
     488             : }
     489             : static GEN
     490          21 : polymini_zi(GEN pol) /* polynome minimal dans Z[i] */
     491             : {
     492          21 :   GEN polh, rac, a0, a1, a2, a3, a4, a5, a6, p = utoipos(3);
     493          21 :   long alpha, beta = 0, t6;
     494             : 
     495          21 :   alpha = ZX_pval(pol,p) & 1;
     496          21 :   polh = alpha? RgX_Rg_div(pol, p): pol;
     497          21 :   rac = mkcomplex(Fp_div(RgX_coeff(polh,3), RgX_coeff(polh,6), p), gen_1);
     498             :   for(;;)
     499           7 :   {
     500             :     long e;
     501          28 :     polh = RgX_translate(polh, rac);
     502          28 :     t6 = theta_3_zi(polh); e = t6 / 6;
     503          28 :     if (e)
     504             :     {
     505          14 :       GEN pe = powiu(p,e);
     506          14 :       polh = RgX_Rg_div(RgX_unscale(polh,pe), powiu(pe,3));
     507          14 :       alpha = (alpha+e)&1;
     508          14 :       t6 -= e * 6; beta += e;
     509             :     }
     510          28 :     RgX_to_06(polh, &a0,&a1,&a2,&a3,&a4,&a5,&a6);
     511          28 :     if (t6 || !myval_zi(a4) || !myval_zi(a5)) break;
     512           7 :     rac = zi_pow3mod(gdiv(a6, gneg(a3)));
     513             :   }
     514          21 :   if (alpha && myval_zi(a0) >= 3 && myval_zi(a1) >= 2 && myval_zi(a2) >= 1)
     515             :   {
     516          14 :     t6 += 6; beta--; alpha = 0;
     517             :   }
     518          21 :   if (alpha && beta >= 1) pari_err_BUG("quadratic");
     519          21 :   return mkvecsmall3(t6, alpha, beta);
     520             : }
     521             : 
     522             : /* pol is a ZX, minimal polynomial over Z_3[i,Y]/(Y^2-3) */
     523             : static GEN
     524          84 : polymini_zi2(GEN pol)
     525             : {
     526             :   long alpha, beta, t6;
     527             :   GEN a0, a1, a2, a3, a4, a5, a6;
     528          84 :   GEN polh, rac, y = pol_x(fetch_var()), p = utoipos(3);
     529             : 
     530          84 :   if (ZX_pval(pol,p)) pari_err_BUG("polymini_zi2 [polynomial not minimal]");
     531          84 :   y = mkpolmod(y, gsubgs(gsqr(y), 3)); /* mod(y,y^2-3) */
     532          84 :   polh = gdivgs(RgX_unscale(pol, y),27); /* H(y*x) / 27 */
     533         161 :   if (myval_zi2(RgX_coeff(polh,4)) <= 0 ||
     534          77 :       myval_zi2(RgX_coeff(polh,2)) <= 0)
     535             :   {
     536           7 :     (void)delete_var();
     537           7 :     return mkvecsmall2(0,0);
     538             :   }
     539             : 
     540          77 :   if (myval_zi2(gsub(RgX_coeff(polh,6), RgX_coeff(polh,0))) > 0)
     541           7 :     rac = gen_I();
     542             :   else
     543          70 :     rac = gen_1;
     544          77 :   alpha = 0;
     545          77 :   beta  = 0;
     546             :   for(;;)
     547           7 :   {
     548             :     long e;
     549          84 :     polh = RgX_translate(polh, rac);
     550          84 :     t6 = theta_3_zi2(polh); e = t6 / 6;
     551          84 :     if (e)
     552             :     {
     553          77 :       GEN pent = gpowgs(y, e);
     554          77 :       polh = RgX_Rg_div(RgX_unscale(polh, pent), gpowgs(pent,3));
     555          77 :       alpha = (alpha+e)&1;
     556          77 :       t6 -= 6*e; beta += e;
     557             :     }
     558          84 :     RgX_to_06(polh, &a0,&a1,&a2,&a3,&a4,&a5,&a6);
     559          84 :     if (t6 || !myval_zi2(a4) || !myval_zi2(a5)) break;
     560           7 :     a3 = liftpol_shallow(a3); if (typ(a3)==t_POL) a3 = RgX_coeff(a3,0);
     561           7 :     a6 = liftpol_shallow(a6); if (typ(a6)==t_POL) a6 = RgX_coeff(a6,0);
     562           7 :     rac = zi_pow3mod(gdiv(a6,gneg(a3)));
     563             :   }
     564          77 :   if (alpha)
     565             :   {
     566          42 :     if (myval_zi2(a0) < 3 || myval_zi2(a1) < 2 || myval_zi2(a2) < 1)
     567           0 :       pari_err_BUG("polymini_zi2 [alpha]");
     568          42 :     t6 += 6; beta--;
     569             :   }
     570          77 :   (void)delete_var();
     571          77 :   if (odd(beta)) pari_err_BUG("quartic [type over Z[i] must be [K-K-(2*m)]]");
     572          77 :   return mkvecsmall2(t6, beta);
     573             : }
     574             : 
     575             : struct igusa {
     576             :   GEN j2, i4, j4, j6, j8, j10, i12;
     577             :   GEN a0, A2, A3, A5, B2;
     578             : };
     579             : struct igusa_p {
     580             :   long eps, eps2, tt, r1, r2, R, tame, abe, tor;
     581             :   GEN p, stable, val, neron;
     582             :   const char *type;
     583             : };
     584             : 
     585             : /* initialize Ip */
     586             : static void
     587        2324 : stable_reduction(struct igusa *I, struct igusa_p *Ip, GEN p)
     588             : {
     589             :   static const long d[9] = { 0,60,30,30,20,15,12,10 }; /* 120 / deg(X) */
     590        2324 :   GEN j2 = I->j2, i4 = I->i4, j4 = I->j4, j6 = I->j6, j8 = I->j8;
     591        2324 :   GEN val, J, v, Ieps, j10 = I->j10, i12 = I->i12;
     592             :   long s, r1, r2, r3, r4, i, eps;
     593             : 
     594        2324 :   Ip->abe = 0;
     595        2324 :   Ip->tor = 0;
     596        2324 :   Ip->tame = 0;
     597        2324 :   Ip->neron = NULL;
     598        2324 :   Ip->type = NULL;
     599        2324 :   Ip->p = p;
     600        2324 :   Ip->val = val = cgetg(9, t_VECSMALL);
     601        2324 :   val[1] = myval(j2,p);
     602        2324 :   val[2] = myval(j4,p);
     603        2324 :   val[3] = myval(i4,p);
     604        2324 :   val[4] = myval(j6,p);
     605        2324 :   val[5] = myval(j8,p);
     606        2324 :   val[6] = myval(j10,p);
     607        2324 :   val[7] = myval(i12,p);
     608        2324 :   switch(itos_or_0(p))
     609             :   {
     610          21 :     case 2:  eps = 4; val[8] = val[5]; Ieps = j8; break;
     611         476 :     case 3:  eps = 3; val[8] = val[4]; Ieps = j6; break;
     612        1827 :     default: eps = 1; val[8] = val[1]; Ieps = gdivgs(j2,12); break;
     613             :   }
     614             : 
     615        2324 :   v = cgetg(8,t_VECSMALL);
     616       18592 :   for(i = 1; i <= 7; i++) v[i] = val[i] * d[i];
     617        2324 :   s = vecsmall_min(v);
     618        2324 :   Ip->eps  = eps;
     619             : 
     620        2324 :   r1 = 3*eps*val[3];
     621        2324 :   r3 = eps*val[6] + val[8];
     622        2324 :   r2 = eps*val[7];
     623        2324 :   r4 = min3(r1, r2, r3);
     624             : 
     625             :   /* s = max(v_p(X) / deg(X)) */
     626        2324 :   J = cgetg(1, t_VEC);
     627        2324 :   if (s == v[6])
     628         280 :     Ip->tt = 1;
     629        2044 :   else if (s == v[7])
     630             :   {
     631         217 :     J = mkvec( Fp_to_mod(gmod(gdiv(gpowgs(i4,3),i12), p), p) );
     632         217 :     Ip->tt = 2;
     633             :   }
     634        1827 :   else if (s == v[3])
     635         350 :     Ip->tt = (val[2] == val[3] || 2*val[4] == 3*val[3])? 3: 4;
     636        1477 :   else if (r3 == r4)
     637             :   {
     638         903 :     GEN a,b, P, sj, pj, t = gmul(gpowgs(j10,eps),Ieps);
     639         903 :     sj = gaddsg(1728, gdiv(gpowgs(i12,eps), t));
     640         903 :     pj = gdiv(gpowgs(i4,3*eps), t);
     641         903 :     a = gmod(sj, p);
     642         903 :     b = gmod(pj, p);
     643         903 :     P = mkpoln(3, gen_1, Fp_neg(a,p), b, 0); /* X^2 - SX + P: roots j1,j2 */
     644         903 :     J = FpX_roots(P, p);
     645         903 :     switch(lg(J)-1)
     646             :     {
     647           0 :       case 0:
     648           0 :         P = FpX_to_mod(P, p);
     649           0 :         a = FpX_to_mod(pol_x(0), p);
     650           0 :         b = FpX_to_mod(deg1pol_shallow(b, gen_m1,0), p);
     651           0 :         J = mkvec2(mkpolmod(a,P), mkpolmod(b,P)); break;
     652         553 :       case 1:
     653         553 :         a = Fp_to_mod(gel(J,1), p);
     654         553 :         J = mkvec2(a, a); break;
     655         350 :       case 2:
     656         350 :         settyp(J, t_VEC);
     657         350 :         J = FpV_to_mod(J, p); break;
     658             :     }
     659         903 :     Ip->tt = 5;
     660             :   }
     661         574 :   else if (r2 == r4)
     662             :   {
     663         413 :     J = mkvec( Fp_to_mod(gmod(gdiv(gpowgs(i4,3),i12), p), p) );
     664         413 :     Ip->tt = 6;
     665             :   }
     666             :   else
     667         161 :     Ip->tt = 7; /* r1 == r4 */
     668        2324 :   Ip->stable = mkvec2(stoi(Ip->tt), J);
     669        2324 : }
     670             : 
     671             : struct red {
     672             :   const char *t, *pages;
     673             :   double tnum;
     674             :   GEN g;
     675             : };
     676             : 
     677             : /* destroy v */
     678             : static GEN
     679        2303 : zv_snf(GEN v)
     680             : {
     681        2303 :   long i, l = lg(v);
     682        5110 :   for (i = 1; i < l; i++)
     683             :   {
     684        2807 :     long j, a = v[i];
     685        4025 :     for (j = i+1; j < l; j++)
     686             :     {
     687        1218 :       long b = v[j], d = ugcd(a,b);
     688        1218 :       v[i] = a = a*(b/d);
     689        1218 :       v[j] = d;
     690             :     }
     691             :   }
     692        2422 :   for (i = l-1; i > 0; i--)
     693        1967 :     if (v[i] != 1) { setlg(v, i+1); break; }
     694        2303 :   return zv_to_ZV(v);
     695             : }
     696             : 
     697             : static GEN
     698        2100 : cyclic(long n)
     699        2100 : { return (n <= 1)? cgetg(1, t_VECSMALL): mkvecsmall(n); }
     700             : static GEN
     701         553 : dicyclic(long a, long b)
     702             : {
     703             :   long d;
     704         553 :   if (!a) a = 1;
     705         553 :   if (!b) b = 1;
     706         553 :   if (a < b) lswap(a,b);
     707         553 :   d = ugcd(a,b);
     708         553 :   if (d == 1) return cyclic(a*b);
     709         462 :   return mkvecsmall2(a*b/d, d);
     710             : }
     711             : /* Z/2xZ/2, resp Z/4 for n even, resp. odd */
     712             : static GEN
     713         462 : groupH(long n) { return odd(n)? cyclic(4): dicyclic(2,2); }
     714             : 
     715             : static long
     716         252 : get_red(struct red *S, struct igusa_p *Ip, GEN polh, GEN p, long alpha, long r)
     717             : {
     718         252 :   GEN val = Ip->val;
     719             :   long indice;
     720         252 :   switch(r)
     721             :   {
     722          42 :     case 0:
     723          42 :       indice = FpX_is_squarefree(FpX_red(polh,p), p)
     724             :                ? 0
     725          42 :                : val[6] - val[7] + val[8]/Ip->eps;
     726          42 :       S->t = stack_sprintf("I{%ld}", indice);
     727          42 :       S->tnum = 1;
     728          42 :       S->pages = "159-177";
     729          42 :       if (indice==0) Ip->abe += 1; else Ip->tor += 1;
     730          42 :       S->g = cyclic(indice);
     731          42 :       return indice ? indice: 1;
     732          35 :     case 6:
     733          35 :       if (alpha == 0) polh = ZX_unscale_divpow(polh, p, 3); /* H(px) /p^3 */
     734          35 :       indice = FpX_is_squarefree(FpX_red(polh,p), p)
     735             :                ? 0
     736          35 :                : val[6] - val[7] + val[8]/Ip->eps;
     737          35 :       S->t = stack_sprintf("I*{%ld}", indice);
     738          35 :       S->tnum = 1.5;
     739          35 :       S->pages = "159-177";
     740          35 :       S->g = groupH(indice);
     741          35 :       return indice + 5;
     742          21 :     case 3:
     743          21 :       S->t = "III";
     744          21 :       S->tnum = 3;
     745          21 :       S->pages = "161-177";
     746          21 :       S->g = cyclic(2);
     747          21 :       return 2;
     748          35 :     case 9:
     749          35 :       S->t = "III*";
     750          35 :       S->tnum = 3.5;
     751          35 :       S->pages = "162-177";
     752          35 :       S->g = cyclic(2);
     753          35 :       return 8;
     754          28 :     case 2:
     755          28 :       S->t = "II";
     756          28 :       S->tnum = 2;
     757          28 :       S->pages = "159-174";
     758          28 :       S->g = cyclic(1);
     759          28 :       return 1;
     760          56 :     case 8:
     761          56 :       S->t = "IV*";
     762          56 :       S->tnum = 4.5;
     763          56 :       S->pages = "160-175";
     764          56 :       S->g = cyclic(3);
     765          56 :       return 7;
     766          21 :     case 4:
     767          21 :       S->t = "IV";
     768          21 :       S->tnum = 4;
     769          21 :       S->pages = "160-174";
     770          21 :       S->g = cyclic(3);
     771          21 :       return 3;
     772          14 :     case 10:
     773          14 :       S->t = "II*";
     774          14 :       S->tnum = 2.5;
     775          14 :       S->pages = "160-174";
     776          14 :       S->g = cyclic(1);
     777          14 :       return 9;
     778           0 :     default: pari_err_BUG("get_red [type]");
     779           0 :       S->t = "";
     780           0 :       S->tnum = 0;
     781           0 :       S->pages = ""; /* gcc -Wall */
     782           0 :       S->g = NULL;
     783             :       return -1; /*LCOV_EXCL_LINE*/
     784             :   }
     785             : }
     786             : 
     787             : /* reduce a/b; assume b > 0 */
     788             : static void
     789        2562 : ssQ_red(long a, long b, long *n, long *d)
     790             : {
     791        2562 :   long g = ugcd(labs(a), b);
     792        2562 :   if (g > 1) { a /= g; b /= g; }
     793        2562 :   *n = a; *d = b;
     794        2562 : }
     795             : /* denom(a/b); assume b > 0 */
     796             : static long
     797          49 : ssQ_denom(long a, long b)
     798             : {
     799          49 :   long g = ugcd(labs(a), b);
     800          49 :   return g == 1? b: b / g;
     801             : }
     802             : /* n = lcm(d, denom(a/b)); r = (a/b * n mod n); assume b > 0 and d > 0 */
     803             : static void
     804         889 : get_nr(long d, long a, long b, long *n, long *r)
     805             : {
     806             :   long c, A, B;
     807         889 :   ssQ_red(a, b, &A,&B);
     808         889 :   c = d / ugcd(d, B);
     809         889 :   *n = B * c;
     810         889 :   *r = umodsu(A * c, *n);
     811         889 : }
     812             : /* n = lcm(denom(a/b), denom(c/d)); r = (a/b * n mod n); q = (c/d * n mod n);
     813             :  * assume b > 0 and d > 0 */
     814             : static void
     815         280 : get_nrq(long a, long b, long c, long d, long *n, long *r, long *q)
     816             : {
     817             :   long g, A, B, C, D;
     818         280 :   ssQ_red(a, b, &A,&B);
     819         280 :   ssQ_red(c, d, &C,&D);
     820         280 :   g = ugcd(B,D);
     821         280 :   *n = B * (D/g);
     822         280 :   *r = umodsu(A * (D/g), *n);
     823         280 :   *q = umodsu(C * (B/g), *n);
     824         280 : }
     825             : 
     826             : /* Ip->tt = 1 */
     827             : static long
     828          49 : tame_1(struct igusa *I, struct igusa_p *Ip)
     829             : {
     830          49 :   GEN p = Ip->p, val = Ip->val;
     831          49 :   long condp = -1, va0, va5, r, n;
     832          49 :   va0 = myval(I->a0,p);
     833          49 :   va5 = myval(I->A5,p);
     834          49 :   if (!gequal0(I->A5) && 20*va0+val[6] > 6*va5)
     835          35 :     get_nr(ssQ_denom(5*val[6]-6*va5, 40), val[6]-2*va5, 20, &n,&r);
     836             :   else
     837          14 :     get_nr(ssQ_denom(5*va0-val[6], 10), 10*va0-val[6], 30, &n,&r);
     838          49 :   switch(n)
     839             :   {
     840           0 :     case 1:
     841           0 :       condp = 0;
     842           0 :       Ip->type = "[I{0-0-0}] page 155";
     843           0 :       Ip->abe = 2; Ip->tor = 0;
     844           0 :       Ip->neron = cyclic(1); break;
     845          35 :     case 2:
     846          35 :       switch(r)
     847             :       {
     848          21 :         case 0:
     849          21 :           condp = 4;
     850          21 :           Ip->type = "[I*{0-0-0}] page 155";
     851          21 :           Ip->neron = mkvecsmall4(2,2,2,2); break;
     852          14 :         case 1:
     853          14 :           condp = 2;
     854          14 :           Ip->type = "[II] page 155";
     855          14 :           Ip->abe = 1; Ip->tor = 0;
     856          14 :           Ip->neron = cyclic(1); break;
     857           0 :         default: pari_err_BUG("tame_1 [bug1]");
     858             :       }
     859          35 :       break;
     860          14 :     case 4:
     861          14 :       condp = 4;
     862          14 :       Ip->type = "[VI] page 156";
     863          14 :       Ip->neron = dicyclic(2,2); break;
     864           0 :     default: pari_err_BUG("tame_1 [bug8]");
     865             :   }
     866          49 :   return condp;
     867             : }
     868             : 
     869             : /* (4.2) */
     870             : static long
     871         371 : tame_234_init(struct igusa *I, struct igusa_p *Ip, long *n, long *q, long *r)
     872             : {
     873         371 :   long va0, va5, vb2, v12 = -1, flc = 1;
     874         371 :   GEN p = Ip->p;
     875         371 :   switch(Ip->tt)
     876             :   {
     877         175 :     case 2: v12 = myval(I->i12,  Ip->p); break;
     878          98 :     case 3: v12 = 3*myval(I->i4, Ip->p); break;
     879          98 :     case 4: v12 = 6*myval(I->j2, Ip->p); break;
     880             :   }
     881         371 :   va0 = myval(I->a0,p);
     882         371 :   va5 = myval(I->A5,p);
     883         371 :   vb2 = myval(I->B2,p);
     884         371 :   if (9*vb2 >= 6*va0+v12 && 36*va5 >= 120*va0+5*v12)
     885             :   {
     886          84 :     get_nrq(12*va0-v12,36, 6*va0-v12,12, n, r, q);
     887             :   }
     888         287 :   else if (120*va0+5*v12 > 36*va5 && 60*vb2 >= 12*va5+5*v12)
     889             :   {
     890          91 :     ssQ_red(36*va5-25*v12,240, q,n);
     891          91 :     *r = umodsu(-2* *q, *n);
     892             :   }
     893             :   else /* 6*va0+v12 > 9*vb2 && 12*va5+5*v12 > 60*vb2 */
     894             :   {
     895         196 :     get_nrq(v12-6*vb2,12, v12-9*vb2,12, n,r,q);
     896         196 :     flc = 0;
     897             :   }
     898         371 :   return flc;
     899             : }
     900             : 
     901             : /* Ip->tt = 2 */
     902             : static long
     903         175 : tame_2(struct igusa *I, struct igusa_p *Ip)
     904             : {
     905         175 :   long condp = -1, d, n, q, r;
     906         175 :   GEN val = Ip->val;
     907         175 :   (void)tame_234_init(I, Ip, &n, &q, &r);
     908         175 :   d = n * (6*val[6]-5*val[7]) / 6;
     909         175 :   switch(n)
     910             :   {
     911          14 :     case 1: condp = 1;
     912          14 :       Ip->type = stack_sprintf("[I{%ld-0-0}] page 170", d);
     913          14 :       Ip->abe = Ip->tor = 1;
     914          14 :       Ip->neron = cyclic(d); break;
     915          42 :     case 2:
     916          42 :       switch(r)
     917             :       {
     918          14 :         case 0: condp = 4;
     919          14 :           Ip->type = stack_sprintf("[I*{%ld-0-0}] page 171",d/2);
     920          14 :           Ip->neron = shallowconcat(dicyclic(2,2),groupH(d/2)); break;
     921          28 :         case 1:
     922          28 :           switch(q)
     923             :           {
     924          14 :             case 0: condp = 2;
     925          14 :               Ip->type = stack_sprintf("[II*{%ld-0}] page 172",d/2);
     926          14 :               Ip->abe = 1; Ip->tor = 0;
     927          14 :               Ip->neron = cyclic(1); break;
     928          14 :             case 1: condp = 3;
     929          14 :               Ip->type = stack_sprintf("[II{%ld-0}] page 171",d/2);
     930          14 :               Ip->abe = 0; Ip->tor = 1;
     931          14 :               Ip->neron = cyclic(2*d); break;
     932           0 :             default: pari_err_BUG("tame2 [bug10]");
     933             :           }
     934          28 :           break;
     935           0 :         default: pari_err_BUG("tame2 [bug11]");
     936             :       }
     937          42 :       break;
     938          28 :     case 3: condp = 3;
     939          28 :       Ip->neron = cyclic(d);
     940          28 :       switch(r)
     941             :       {
     942          14 :         case 1:
     943          14 :           Ip->type = stack_sprintf("[II{%ld}-IV] page 175", (d-2)/3);
     944          14 :           Ip->abe = 0; Ip->tor = 1;
     945          14 :           break;
     946          14 :         case 2:
     947          14 :           Ip->type = stack_sprintf("[II{%ld}-IV*] page 175", (d-1)/3);
     948          14 :           Ip->abe = 0; Ip->tor = 1;
     949          14 :           break;
     950           0 :         default: pari_err_BUG("tame2 [bug12]");
     951             :       }
     952          28 :       break;
     953          77 :     case 4:
     954          77 :       switch(r)
     955             :       {
     956          35 :         case 1:
     957          35 :           switch(q)
     958             :           {
     959          21 :             case 1: condp = 3;
     960          21 :               Ip->type = stack_sprintf("[II{%ld}-III] page 177",(d-2)/4);
     961          21 :               Ip->abe = 0; Ip->tor = 1;
     962          21 :               Ip->neron = cyclic(d/2); break;
     963          14 :             case 3: condp = 4;
     964          14 :               Ip->type = stack_sprintf("[II*{%ld}-III*] page 178",(d-2)/4);
     965          14 :               Ip->abe = 0; Ip->tor = 0;
     966          14 :               Ip->neron = cyclic(8); break;
     967           0 :             default: pari_err_BUG("tame2 [bug13]");
     968             :           }
     969          35 :           break;
     970          42 :         case 3:
     971          42 :           switch(q)
     972             :           {
     973          14 :             case 1: condp = 4;
     974          14 :               Ip->type = stack_sprintf("[II*{%ld}-III] page 178",(d-2)/4);
     975          14 :               Ip->abe = 0; Ip->tor = 0;
     976          14 :               Ip->neron = cyclic(8); break;
     977          28 :             case 3: condp = 3;
     978          28 :               Ip->type = stack_sprintf("[II{%ld}-III*] page 178",(d-2)/4);
     979          28 :               Ip->abe = 0; Ip->tor = 1;
     980          28 :               Ip->neron = cyclic(d/2); break;
     981           0 :             default: pari_err_BUG("tame2 [bug14]");
     982             :           }
     983          42 :           break;
     984           0 :         default: pari_err_BUG("tame2 [bug15]");
     985             :       }
     986          77 :       break;
     987          14 :     case 6:
     988          14 :       switch(r)
     989             :       {
     990          14 :         case 2: condp = 4;
     991          14 :           Ip->type = stack_sprintf("[II*-II*{%ld}] page 176", (d-4)/6);
     992          14 :           Ip->abe = 0; Ip->tor = 0;
     993          14 :           Ip->neron = groupH((d+2)/6); break;
     994           0 :         case 4: condp = 4;
     995           0 :           Ip->type = stack_sprintf("[II-II*{%ld}] page 176", (d-2)/6);
     996           0 :           Ip->abe = 0; Ip->tor = 0;
     997           0 :           Ip->neron = groupH((d+4)/6); break;
     998           0 :         default: pari_err_BUG("tame2 [bug16]");
     999             :       }
    1000          14 :       break;
    1001           0 :     default: pari_err_BUG("tame2 [bug17]");
    1002             :   }
    1003         175 :   return condp;
    1004             : }
    1005             : 
    1006             : /* Ip->tt = 3 */
    1007             : static long
    1008          98 : tame_3(struct igusa *I, struct igusa_p *Ip)
    1009             : {
    1010          98 :   long condp = -1, n, q, r, va5, d1, d2;
    1011          98 :   long flc = tame_234_init(I, Ip, &n, &q, &r);
    1012          98 :   GEN val = Ip->val;
    1013             : 
    1014          98 :   va5 = 2*val[6]-5*val[3];
    1015          98 :   d1 = minss(n * (val[7]-3*val[3]), n * va5 / 4);
    1016          98 :   d2 = n * va5 / 2 - d1;
    1017          98 :   switch(n)
    1018             :   {
    1019          21 :     case 1: condp = 2;
    1020          21 :       Ip->type = stack_sprintf("[I{%ld-%ld-0}] page 179", d1,d2);
    1021          21 :       Ip->abe = 0; Ip->tor = 2;
    1022          21 :       Ip->neron = dicyclic(d1,d2); break;
    1023          49 :     case 2:
    1024          49 :       switch(r)
    1025             :       {
    1026          21 :         case 0: condp = 4;
    1027          21 :           Ip->type = stack_sprintf("[I*{%ld-%ld-0}] page 180", d1/2,d2/2);
    1028          21 :           Ip->neron = shallowconcat(groupH(d1/2),groupH(d2/2)); break;
    1029          28 :         case 1: condp = 3;
    1030          28 :           if (flc)
    1031             :           {
    1032          28 :             Ip->type = stack_sprintf("[2I{%ld}-0] page 181", d1);
    1033          28 :             Ip->abe = 0; Ip->tor = 1;
    1034          28 :             Ip->neron = cyclic(d1);
    1035             :           }
    1036             :           else
    1037             :           { /* FIXME: "or" same with d1<->d2 */
    1038           0 :             Ip->type = stack_sprintf("[II{%ld-%ld}] page 182",d1/2,d2/2);
    1039           0 :             Ip->abe = 0; Ip->tor = 1;
    1040           0 :             Ip->neron = ((d1*d2-4)&7)? cyclic(2*d1): dicyclic(d1,2);
    1041             :           }
    1042          28 :           break;
    1043           0 :         default: pari_err_BUG("tame3 [bug20]");
    1044             :       }
    1045          49 :       break;
    1046          28 :     case 4: condp = 4;
    1047          28 :       Ip->type = stack_sprintf("[III{%ld}] page 182", d1/2);
    1048          28 :       Ip->neron = groupH(d1/2); break;
    1049           0 :     default: pari_err_BUG("tame3 [bug21]");
    1050             :   }
    1051          98 :   return condp;
    1052             : }
    1053             : 
    1054             : /* Ip->tt = 4 */
    1055             : static long
    1056          98 : tame_4(struct igusa *I, struct igusa_p *Ip)
    1057             : {
    1058          98 :   long condp = -1, d1,d2,d3, f1,f2, g, h, n, q, r, vl,vn,vm, e1,e2,e3;
    1059          98 :   GEN val = Ip->val;
    1060          98 :   (void)tame_234_init(I, Ip, &n, &q, &r);
    1061          98 :   vl = val[6]-5*val[1];
    1062          98 :   vn = val[7]-6*val[1];
    1063          98 :   vm = val[2]-2*val[1]; /* all >= 0 */
    1064          98 :   e1 = min3(2*vl, 3*vn, 6*vm);
    1065          98 :   e2 = minss(6*vl - e1, 12*vn - 2*e1); /* >= 0 */
    1066          98 :   e3 = 12*vl - (2*e1+e2); /* >= 0 */
    1067          98 :   d1 = e1*n / 6;
    1068          98 :   d2 = e2*n / 12;
    1069          98 :   d3 = e3*n / 12;
    1070          98 :   g = d1*d2 + d1*d3 + d2*d3;
    1071          98 :   h = ugcd(ugcd(d1,d2),d3);
    1072          98 :   switch(n)
    1073             :   {
    1074          14 :     case 1: condp = 2;
    1075          14 :       Ip->type = stack_sprintf("[I{%ld-%ld-%ld}] page 182",d1,d2,d3);
    1076          14 :       Ip->abe = 0; Ip->tor = 2;
    1077          14 :       Ip->neron = dicyclic(h,g/h); break;
    1078          84 :     case 2:
    1079          84 :       switch(r)
    1080             :       {
    1081          14 :         case 0: condp = 4;
    1082          14 :           Ip->type = stack_sprintf("[I*{%ld-%ld-%ld}] page 183",d1/2,d2/2,d3/2);
    1083          14 :           Ip->neron = shallowconcat(groupH(g/4), groupH(2-((h&2)>>1))); break;
    1084          70 :         case 1:
    1085          70 :           if      (d1 == d2 || d1 == d3) f2 = d1;
    1086           0 :           else if (d2 == d3) f2 = d2;
    1087             :           else {
    1088           0 :             pari_err_BUG("tame4 [bug23]");
    1089             :             return -1; /*LCOV_EXCL_LINE*/
    1090             :           }
    1091          70 :           f1 = d1+d2+d3-2*f2;
    1092          70 :           switch(q)
    1093             :           {
    1094          28 :             case 0: condp = 3;
    1095          28 :               Ip->type = stack_sprintf("[II*{%ld-%ld}] page 184", f1/2,f2);
    1096          28 :               Ip->abe = 0; Ip->tor = 1;
    1097          28 :               Ip->neron = cyclic(f2); break;
    1098          42 :             case 1: condp = 3;
    1099          42 :               Ip->type = stack_sprintf("[II{%ld-%ld}] page 183", f1/2,f2);
    1100          42 :               Ip->abe = 0; Ip->tor = 1;
    1101          42 :               Ip->neron = cyclic(2*f1+f2); break;
    1102           0 :             default: pari_err_BUG("tame4 [bug24]");
    1103             :           }
    1104          70 :           break;
    1105           0 :         default: pari_err_BUG("tame4 [bug25]");
    1106             :       }
    1107          84 :       break;
    1108           0 :     case 3: condp = 4;
    1109           0 :       Ip->type = stack_sprintf("[III{%ld}] page 184",d1);
    1110           0 :       Ip->abe = 0; Ip->tor = 0;
    1111           0 :       Ip->neron = (d1%3)? cyclic(9): dicyclic(3,3); break;
    1112           0 :     case 6: condp = 4;
    1113           0 :       Ip->type = stack_sprintf("[III*{%ld}] page 184",d1/2);
    1114           0 :       Ip->abe = 0; Ip->tor = 0;
    1115           0 :       Ip->neron = cyclic(1); break;
    1116           0 :     default: pari_err_BUG("tame4 [bug26]");
    1117             :   }
    1118          98 :   return condp;
    1119             : }
    1120             : 
    1121             : /* p = 3 */
    1122             : static void
    1123          91 : tame_567_init_3(struct igusa_p *Ip, long dk,
    1124             :                 long *pd, long *pn, long *pdm, long *pr)
    1125             : {
    1126          91 :   long n = 1 + Ip->r1/6;
    1127          91 :   *pd = n * dk / 36; /* / (12*Ip->eps) */
    1128          91 :   *pn = n;
    1129          91 :   *pr = -1; /* unused */
    1130          91 :   *pdm = 0;
    1131          91 : }
    1132             : 
    1133             : /* (4.3) */
    1134             : static void
    1135        1113 : tame_567_init(struct igusa *I, struct igusa_p *Ip, long dk,
    1136             :               long *pd, long *pn, long *pdm, long *pr)
    1137             : {
    1138             :   long ndk, ddk;
    1139        1113 :   GEN p = Ip->p, val = Ip->val;
    1140             : 
    1141        1113 :   if (equaliu(p,3)) { tame_567_init_3(Ip, dk, pd, pn, pdm, pr); return; }
    1142             :   /* assume p > 3, Ip->eps = 1 */
    1143        1022 :   ssQ_red(dk, 12, &ndk, &ddk);
    1144        1022 :   if (! odd(val[8]))
    1145             :   {
    1146         840 :     long va0 = myval(I->a0,p), va2 = myval(I->A2,p), va3 = myval(I->A3,p);
    1147         840 :     long va5 = myval(I->A5,p), vb2 = myval(I->B2,p);
    1148         840 :     long v1 = 2*va3-4*va0-val[1],   v2 = 6*va5-20*va0-5*val[1];
    1149         840 :     long v3 = 3*vb2-2*va0-2*val[1], v4 = 10*vb2-2*va5-5*val[1];
    1150         840 :     if (v3 >= 0 && v2 >= 0 && v1 >= 0)
    1151             :     {
    1152         483 :       if (v1==0 || v2==0) get_nr(ddk, va0+val[1], 6,pn,pr); /* Prop 4.3.1 (a) */
    1153             :       else
    1154             :       { /* Prop 4.3.1 (d) */
    1155         455 :         long v5 = myval(subii(mulii(I->A2,I->A3),mului(3,I->A5)),p);
    1156         455 :         if (gequal0(I->A2)) pari_err_BUG("tame567 [bug27]");
    1157         455 :         get_nr(ddk, 12*va0 + min3(dk, 6*va3-9*va2, 4*v5 - 10*va2), 24, pn,pr);
    1158             :       }
    1159             :     }
    1160         357 :     else if (v2 < 0 && v4 >= 0)
    1161         357 :       get_nr(ddk, 2*va5+val[1], 8, pn,pr); /* Prop 4.3.1 (b) */
    1162             :     else /* (v3 < 0 && v4 < 0) */
    1163           0 :       get_nr(ddk, vb2, 4, pn,pr); /* Prop 4.3.1 (c) */
    1164         840 :     *pd = (*pn/ddk) * ndk;
    1165             :   }
    1166             :   else
    1167             :   {
    1168         182 :     *pr = ndk;
    1169         182 :     *pn = 2*ddk;
    1170         182 :     *pd = 2*ndk;
    1171             :   }
    1172        1022 :   *pdm = umodsu(*pd, *pn);
    1173             : }
    1174             : 
    1175             : static long
    1176         651 : tame_5(struct igusa *I, struct igusa_p *Ip)
    1177             : {
    1178         651 :   long condp = -1, d, n, dm, r, dk;
    1179         651 :   GEN val = Ip->val;
    1180             : 
    1181         651 :   dk = Ip->eps*val[6]-5*val[8];
    1182         651 :   tame_567_init(I, Ip, dk, &d, &n, &dm, &r);
    1183         651 :   if (! odd(val[8]))
    1184             :   {
    1185         525 :     switch(n)
    1186             :     {
    1187          14 :       case 1: condp = 0;
    1188          14 :         Ip->type = stack_sprintf("[I{0}-I{0}-%ld] page 158", d);
    1189          14 :         Ip->abe = 2; Ip->tor = 0;
    1190          14 :         Ip->neron = cyclic(1); break;
    1191          28 :       case 2:
    1192          28 :         switch(dm)
    1193             :         {
    1194          14 :           case 0: condp = 4;
    1195          14 :             Ip->type = stack_sprintf("[I*{0}-I*{0}-%ld] page 158",(d-2)/2);
    1196          14 :             Ip->abe = 0; Ip->tor = 0;
    1197          14 :             Ip->neron = mkvecsmall4(2,2,2,2); break;
    1198          14 :           case 1: condp = 2;
    1199          14 :             Ip->type = stack_sprintf("[I{0}-I*{0}-%ld] page 159",(d-1)/2);
    1200          14 :             Ip->abe = 1; Ip->tor = 0;
    1201          14 :             Ip->neron = dicyclic(2,2); break;
    1202             :         }
    1203          28 :         break;
    1204          70 :       case 3:
    1205          70 :         switch(dm)
    1206             :         {
    1207          14 :           case 0: condp = 4;
    1208          14 :             Ip->type = stack_sprintf("[IV-IV*-%ld] page 165",(d-3)/3);
    1209          14 :             Ip->abe = 0; Ip->tor = 0;
    1210          14 :             Ip->neron = dicyclic(3,3); break;
    1211          28 :           case 1:
    1212          28 :             switch(r)
    1213             :             {
    1214          14 :               case 0: case 1: condp = 2;
    1215          14 :                 Ip->type = stack_sprintf("[I{0}-IV-%ld] page 160",(d-1)/3);
    1216          14 :                 Ip->abe = 1; Ip->tor = 0;
    1217          14 :                 Ip->neron = cyclic(3); break;
    1218          14 :               case 2: condp = 4;
    1219          14 :                 Ip->type = stack_sprintf("[IV*-IV*-%ld] page 166",(d-4)/3);
    1220          14 :                 Ip->abe = 0; Ip->tor = 0;
    1221          14 :                 Ip->neron = dicyclic(3,3); break;
    1222             :             }
    1223          28 :             break;
    1224          28 :           case 2:
    1225          28 :             switch(r)
    1226             :             {
    1227          14 :               case 0: case 2: condp = 2;
    1228          14 :                 Ip->type = stack_sprintf("[I{0}-IV*-%ld] page 160",(d-2)/3);
    1229          14 :                 Ip->abe = 1; Ip->tor = 0;
    1230          14 :                 Ip->neron = cyclic(3); break;
    1231          14 :               case 1: condp = 4;
    1232          14 :                 Ip->type = stack_sprintf("[IV-IV-%ld] page 165",(d-2)/3);
    1233          14 :                 Ip->abe = 0; Ip->tor = 0;
    1234          14 :                 Ip->neron = dicyclic(3,3); break;
    1235             :             }
    1236          28 :             break;
    1237             :         }
    1238          70 :         break;
    1239          98 :       case 4:
    1240          98 :         switch(dm)
    1241             :         {
    1242          14 :           case 0: condp = 4;
    1243          14 :             Ip->type = stack_sprintf("[III-III*-%ld] page 169",(d-4)/4);
    1244          14 :             Ip->abe = 0; Ip->tor = 0;
    1245          14 :             Ip->neron = dicyclic(2,2); break;
    1246          28 :           case 1:
    1247          28 :             switch(r)
    1248             :             {
    1249          14 :               case 0: case 1: condp = 2;
    1250          14 :                 Ip->type = stack_sprintf("[I{0}-III-%ld] page 161",(d-1)/4);
    1251          14 :                 Ip->abe = 1; Ip->tor = 0;
    1252          14 :                 Ip->neron = cyclic(2); break;
    1253          14 :               case 2: case 3: condp = 4;
    1254          14 :                 Ip->type = stack_sprintf("[I*{0}-III*-%ld] page 162",(d-5)/4);
    1255          14 :                 Ip->abe = 0; Ip->tor = 0;
    1256          14 :                 Ip->neron = mkvecsmall3(2,2,2); break;
    1257             :             }
    1258          28 :             break;
    1259          28 :           case 2: condp = 4;
    1260          28 :             Ip->neron = dicyclic(2,2);
    1261          28 :             switch(r)
    1262             :             {
    1263          14 :               case 1:
    1264          14 :                 Ip->type = stack_sprintf("[III-III-%ld] page 169",(d-2)/4);
    1265          14 :                 break;
    1266          14 :               case 3:
    1267          14 :                 Ip->type = stack_sprintf("[III*-III*-%ld] page 169",(d-6)/4);
    1268          14 :                 break;
    1269           0 :               default: pari_err_BUG("tame5 [bug29]");
    1270             :             }
    1271          28 :             break;
    1272          28 :           case 3:
    1273          28 :             switch(r)
    1274             :             {
    1275          14 :               case 0: case 3: condp = 2;
    1276          14 :                 Ip->type = stack_sprintf("[I{0}-III*-%ld] page 162",(d-3)/4);
    1277          14 :                 Ip->abe = 1; Ip->tor = 0;
    1278          14 :                 Ip->neron = cyclic(2); break;
    1279          14 :               case 1: case 2: condp = 4;
    1280          14 :                 Ip->type = stack_sprintf("[I*{0}-III-%ld] page 162",(d-3)/4);
    1281          14 :                 Ip->abe = 0; Ip->tor = 0;
    1282          14 :                 Ip->neron = mkvecsmall3(2,2,2); break;
    1283             :             }
    1284          28 :             break;
    1285             :         }
    1286          98 :         break;
    1287         203 :       case 6:
    1288         203 :         switch(dm)
    1289             :         {
    1290          14 :           case 0: condp = 4;
    1291          14 :             Ip->type = stack_sprintf("[II-II*-%ld] page 163",(d-6)/6);
    1292          14 :             Ip->abe = 0; Ip->tor = 0;
    1293          14 :             Ip->neron = cyclic(1); break;
    1294          42 :           case 1:
    1295          42 :             switch(r)
    1296             :             {
    1297          14 :               case 0: case 1: condp = 2;
    1298          14 :                 Ip->type = stack_sprintf("[I{0}-II-%ld] page 159",(d-1)/6);
    1299          14 :                 Ip->abe = 1; Ip->tor = 0;
    1300          14 :                 Ip->neron = cyclic(1); break;
    1301          14 :               case 2: case 5: condp = 4;
    1302          14 :                 Ip->type = stack_sprintf("[II*-IV-%ld] page 164",(d-7)/6);
    1303          14 :                 Ip->abe = 0; Ip->tor = 0;
    1304          14 :                 Ip->neron = cyclic(3); break;
    1305          14 :               case 3: case 4: condp = 4;
    1306          14 :                 Ip->type = stack_sprintf("[I*{0}-IV*-%ld] page 161",(d-7)/6);
    1307          14 :                 Ip->abe = 0; Ip->tor = 0;
    1308          14 :                 Ip->neron = mkvecsmall2(6,2); break;
    1309             :             }
    1310          42 :             break;
    1311          35 :           case 2:
    1312          35 :             switch(r)
    1313             :             {
    1314          21 :               case 1: condp = 4;
    1315          21 :                 Ip->type = stack_sprintf("[II-II-%ld] page 163",(d-2)/6);
    1316          21 :                 Ip->abe = 0; Ip->tor = 0;
    1317          21 :                 Ip->neron = cyclic(1); break;
    1318          14 :               case 3: case 5: condp = 4;
    1319          14 :                 Ip->type = stack_sprintf("[I*{0}-II*-%ld] page 160",(d-8)/6);
    1320          14 :                 Ip->abe = 0; Ip->tor = 0;
    1321          14 :                 Ip->neron = dicyclic(2,2); break;
    1322           0 :               default: pari_err_BUG("tame5 [bug30]");
    1323             :             }
    1324          35 :             break;
    1325          28 :           case 3:
    1326          28 :             Ip->neron = cyclic(3);
    1327          28 :             switch(r)
    1328             :             {
    1329          14 :               case 1: case 2: condp = 4;
    1330          14 :                 Ip->type = stack_sprintf("[II-IV-%ld] page 164",(d-3)/6);
    1331          14 :                 break;
    1332          14 :               case 4: case 5: condp = 4;
    1333          14 :                 Ip->type = stack_sprintf("[II*-IV*-%ld] page 164",(d-9)/6);
    1334          14 :                 break;
    1335           0 :               default: pari_err_BUG("tame5 [bug31]");
    1336             :             }
    1337          28 :             break;
    1338          42 :           case 4:
    1339          42 :             switch(r)
    1340             :             {
    1341          14 :               case 1: case 3: condp = 4;
    1342          14 :                 Ip->type = stack_sprintf("[I*{0}-II-%ld] page 160",(d-4)/6);
    1343          14 :                 Ip->neron = dicyclic(2,2); break;
    1344          28 :               case 5: condp = 4;
    1345          28 :                 Ip->type = stack_sprintf("[II*-II*-%ld] page 163",(d-10)/6);
    1346          28 :                 Ip->neron = cyclic(1); break;
    1347           0 :               default: pari_err_BUG("tame5 [bug32]");
    1348             :             }
    1349          42 :             break;
    1350          42 :           case 5:
    1351          42 :             switch(r)
    1352             :             {
    1353          14 :               case 0: case 5: condp = 2;
    1354          14 :                 Ip->type = stack_sprintf("[I{0}-II*-%ld] page 160",(d-5)/6);
    1355          14 :                 Ip->abe = 1; Ip->tor = 0;
    1356          14 :                 Ip->neron = cyclic(1); break;
    1357          14 :               case 1: case 4: condp = 4;
    1358          14 :                 Ip->type = stack_sprintf("[II-IV*-%ld] page 164",(d-5)/6);
    1359          14 :                 Ip->abe = 0; Ip->tor = 0;
    1360          14 :                 Ip->neron = cyclic(3); break;
    1361          14 :               case 2: case 3: condp = 4;
    1362          14 :                 Ip->type = stack_sprintf("[I*{0}-IV-%ld] page 161",(d-5)/6);
    1363          14 :                 Ip->abe = 0; Ip->tor = 0;
    1364          14 :                 Ip->neron = mkvecsmall2(6,2); break;
    1365             :             }
    1366          42 :             break;
    1367           0 :           default: pari_err_BUG("tame5 [bug33]");
    1368             :         }
    1369         203 :         break;
    1370         112 :       case 12:
    1371         112 :         condp = 4;
    1372         112 :         switch(dm)
    1373             :         {
    1374          28 :           case 1:
    1375          28 :             switch(r)
    1376             :             {
    1377          14 :               case 3: case 10:
    1378          14 :                 Ip->type = stack_sprintf("[II*-III-%ld] page 166",(d-13)/12);
    1379          14 :                 Ip->neron = cyclic(2); break;
    1380          14 :               case 4: case 9:
    1381          14 :                 Ip->type = stack_sprintf("[III*-IV-%ld] page 167",(d-13)/12);
    1382          14 :                 Ip->neron = cyclic(6); break;
    1383           0 :               default: pari_err_BUG("tame5 [bug34]");
    1384             :             }
    1385          28 :             break;
    1386          28 :           case 5:
    1387          28 :             switch(r)
    1388             :             {
    1389          14 :               case 2: case 3:
    1390          14 :                 Ip->type = stack_sprintf("[II-III-%ld] page 166",(d-5)/12);
    1391          14 :                 Ip->neron = cyclic(2); break;
    1392          14 :               case 8: case 9:
    1393          14 :                 Ip->type = stack_sprintf("[III*-IV*-%ld] page 168",(d-17)/12);
    1394          14 :                 Ip->neron = cyclic(6); break;
    1395           0 :               default: pari_err_BUG("tame5 [bug35]");
    1396             :             }
    1397          28 :             break;
    1398          28 :           case 7:
    1399          28 :             switch(r)
    1400             :             {
    1401          14 :               case 3: case 4:
    1402          14 :                 Ip->type = stack_sprintf("[III-IV-%ld] page 167",(d-7)/12);
    1403          14 :                 Ip->neron = cyclic(6); break;
    1404          14 :               case 9: case 10:
    1405          14 :                 Ip->type = stack_sprintf("[II*-III*-%ld] page 167",(d-19)/12);
    1406          14 :                 Ip->neron = cyclic(2); break;
    1407           0 :               default: pari_err_BUG("tame5 [bug36]");
    1408             :             }
    1409          28 :             break;
    1410          28 :           case 11:
    1411          28 :             switch(r)
    1412             :             {
    1413          14 :               case 3: case 8:
    1414          14 :                 Ip->type = stack_sprintf("[III-IV*-%ld] page 168",(d-11)/12);
    1415          14 :                 Ip->neron = cyclic(6); break;
    1416          14 :               case 2: case 9:
    1417          14 :                 Ip->type = stack_sprintf("[II-III*-%ld] page 166",(d-11)/12);
    1418          14 :                 Ip->neron = cyclic(2); break;
    1419           0 :               default: pari_err_BUG("tame5 [bug37]");
    1420             :             }
    1421          28 :             break;
    1422           0 :           default: pari_err_BUG("tame5 [bug38]");
    1423             :         }
    1424         112 :         break;
    1425           0 :       default: pari_err_BUG("tame5 [bug39]");
    1426             :     }
    1427             :   }
    1428             :   else
    1429             :   {
    1430         126 :     r %= (n >> 1);
    1431         126 :     switch(n)
    1432             :     {
    1433          14 :       case 2: condp = 2;
    1434          14 :         Ip->type = stack_sprintf("[2I{0}-%ld] page 159",(d/2));
    1435          14 :         Ip->abe = 1; Ip->tor = 0;
    1436          14 :         Ip->neron = cyclic(1); break;
    1437          28 :       case 4: condp = 4;
    1438          28 :         Ip->type = stack_sprintf("[2I*{0}-%ld] page 159",(d/2-1)/2);
    1439          28 :         Ip->abe = 0; Ip->tor = 0;
    1440          28 :         Ip->neron = dicyclic(2,2); break;
    1441          28 :       case 6: condp = 4;
    1442          28 :         Ip->neron = cyclic(3);
    1443          28 :         switch(r)
    1444             :           {
    1445          14 :           case 1:
    1446          14 :             Ip->type = stack_sprintf("[2IV-%ld] page 165",(d/2-1)/3);
    1447          14 :             break;
    1448          14 :           case 2:
    1449          14 :             Ip->type = stack_sprintf("[2IV*-%ld] page 165",(d/2-2)/3);
    1450          14 :             break;
    1451           0 :           default: pari_err_BUG("tame5 [bug40]");
    1452             :           }
    1453          28 :         break;
    1454          28 :       case 8: condp = 4;
    1455          28 :         Ip->neron = cyclic(2);
    1456          28 :         switch(r)
    1457             :         {
    1458          14 :           case 1:
    1459          14 :             Ip->type = stack_sprintf("[2III-%ld] page 168",(d/2-1)/4);
    1460          14 :             break;
    1461          14 :           case 3:
    1462          14 :             Ip->type = stack_sprintf("[2III*-%ld] page 168",(d/2-3)/4);
    1463          14 :             break;
    1464           0 :           default: pari_err_BUG("tame5 [bug41]");
    1465             :         }
    1466          28 :         break;
    1467          28 :       case 12: condp = 4;
    1468          28 :         Ip->neron = cyclic(1);
    1469          28 :         switch(r)
    1470             :         {
    1471          14 :           case 1:
    1472          14 :             Ip->type = stack_sprintf("[2II-%ld] page 162",(d/2-1)/6);
    1473          14 :             break;
    1474          14 :           case 5:
    1475          14 :             Ip->type = stack_sprintf("[2II*-%ld] page 163",(d/2-5)/6);
    1476          14 :             break;
    1477           0 :           default: pari_err_BUG("tame5 [bug42]");
    1478             :         }
    1479          28 :         break;
    1480           0 :       default: pari_err_BUG("tame5 [bug43]");
    1481             :     }
    1482             :   }
    1483         651 :   return condp;
    1484             : }
    1485             : 
    1486             : static long
    1487         322 : tame_6(struct igusa *I, struct igusa_p *Ip)
    1488             : {
    1489         322 :   long condp = -1, d, d1, n, dm, r, dk;
    1490         322 :   GEN val = Ip->val;
    1491             : 
    1492         322 :   dk = Ip->eps*val[7]-6*val[8];
    1493         322 :   tame_567_init(I, Ip, dk, &d, &n, &dm, &r);
    1494         322 :   d1 = n * (Ip->eps*(val[6]-val[7])+val[8]) / Ip->eps;
    1495         322 :   switch(n)
    1496             :   {
    1497          63 :     case 1: condp = 1;
    1498          63 :       Ip->type = stack_sprintf("[I{0}-I{%ld}-%ld] page 170",d1,d);
    1499          63 :       Ip->abe = Ip->tor = 1;
    1500          63 :       Ip->neron = cyclic(d1); break;
    1501          49 :     case 2:
    1502          49 :       switch(dm)
    1503             :       {
    1504          14 :         case 0: condp = 4;
    1505          14 :           Ip->type=stack_sprintf("[I*{0}-I*{%ld}-%ld] page 171", d1/2,(d-2)/2);
    1506          14 :           Ip->neron = shallowconcat(groupH(d1/2), dicyclic(2,2)); break;
    1507          35 :         case 1: return -1;
    1508           0 :         default: pari_err_BUG("tame6 [bug44]");
    1509             :       }
    1510          14 :       break;
    1511          28 :     case 3: condp = 3;
    1512          28 :       Ip->neron = dicyclic(3,d1/3);
    1513          28 :       switch(dm)
    1514             :       {
    1515          14 :         case 1:
    1516          14 :           Ip->type = stack_sprintf("[I{%ld}-IV-%ld] page 173",d1/3,(d-1)/3);
    1517          14 :           Ip->abe = 0; Ip->tor = 1;
    1518          14 :           break;
    1519          14 :         case 2:
    1520          14 :           Ip->type = stack_sprintf("[I{%ld}-IV*-%ld] page 173",d1/3,(d-2)/3);
    1521          14 :           Ip->abe = 0; Ip->tor = 1;
    1522          14 :           break;
    1523           0 :         default: pari_err_BUG("tame6 [bug45]");
    1524             :       }
    1525          28 :       break;
    1526          70 :     case 4:
    1527          70 :       switch(dm)
    1528             :       {
    1529          42 :         case 1:
    1530          42 :           switch(r)
    1531             :           {
    1532          14 :             case 0: case 1: condp = 3;
    1533          14 :               Ip->type=stack_sprintf("[I{%ld}-III-%ld] page 176",d1/4,(d-1)/4);
    1534          14 :               Ip->abe = 0; Ip->tor = 1;
    1535          14 :               Ip->neron = dicyclic(2,d1/4); break;
    1536          28 :             case 2: case 3: condp = 4;
    1537          28 :               Ip->type=stack_sprintf("[I*{%ld}-III*-%ld] page 177",d1/4,(d-5)/4);
    1538          28 :               Ip->abe = 0; Ip->tor = 0;
    1539          28 :               Ip->neron = shallowconcat(groupH(d1/4), cyclic(2)); break;
    1540           0 :             default: pari_err_BUG("tame6 [bug46]");
    1541             :           }
    1542          42 :           break;
    1543          28 :         case 3:
    1544          28 :           switch(r)
    1545             :           {
    1546          14 :             case 0: case 3: condp = 3;
    1547          14 :               Ip->type=stack_sprintf("[I{%ld}-III*-%ld] page 176",d1/4,(d-3)/4);
    1548          14 :               Ip->abe = 0; Ip->tor = 1;
    1549          14 :               Ip->neron = dicyclic(2,d1/4); break;
    1550          14 :             case 1: case 2: condp = 4;
    1551          14 :               Ip->type=stack_sprintf("[I*{%ld}-III-%ld] page 177",d1/4,(d-3)/4);
    1552          14 :               Ip->abe = 0; Ip->tor = 0;
    1553          14 :               Ip->neron = shallowconcat(groupH(d1/4), cyclic(2)); break;
    1554           0 :             default: pari_err_BUG("tame6 [bug47]");
    1555             :           }
    1556          28 :           break;
    1557           0 :         default: pari_err_BUG("tame6 [bug48]");
    1558             :       }
    1559          70 :       break;
    1560         112 :     case 6:
    1561         112 :       switch(dm)
    1562             :       {
    1563          42 :         case 1:
    1564          42 :           switch(r)
    1565             :           {
    1566          14 :             case 0: case 1: condp = 3;
    1567          14 :               Ip->type = stack_sprintf("[I{%ld}-II-%ld] page 172",d1/6,(d-1)/6);
    1568          14 :               Ip->abe = 0; Ip->tor = 1;
    1569          14 :               Ip->neron = cyclic(d1/6); break;
    1570          28 :             case 3: case 4: condp = 4;
    1571          28 :               Ip->type=stack_sprintf("[I*{%ld}-IV*-%ld] page 174",d1/6,(d-7)/6);
    1572          28 :               Ip->abe = 0; Ip->tor = 0;
    1573          28 :               Ip->neron = shallowconcat(groupH(d1/6), cyclic(3)); break;
    1574           0 :             default: pari_err_BUG("tame6 [bug49]");
    1575             :           }
    1576          42 :           break;
    1577          28 :         case 2: condp = 4;
    1578          28 :           Ip->type = stack_sprintf("[I*{%ld}-II*-%ld] page 174",d1/6,(d-8)/6);
    1579          28 :           Ip->abe = 0; Ip->tor = 0;
    1580          28 :           Ip->neron = groupH(d1/6); break;
    1581          14 :         case 4: condp = 4;
    1582          14 :           Ip->type = stack_sprintf("[I*{%ld}-II-%ld] page 173",d1/6,(d-4)/6);
    1583          14 :           Ip->abe = 0; Ip->tor = 0;
    1584          14 :           Ip->neron = groupH(d1/6); break;
    1585          28 :         case 5:
    1586          28 :           switch(r)
    1587             :           {
    1588          14 :             case 0: case 5: condp = 3;
    1589          14 :               Ip->type=stack_sprintf("[I{%ld}-II*-%ld] page 172",d1/6,(d-5)/6);
    1590          14 :               Ip->abe = 0; Ip->tor = 1;
    1591          14 :               Ip->neron = cyclic(d1/6); break;
    1592          14 :             case 2: case 3: condp = 4;
    1593          14 :               Ip->type=stack_sprintf("[I*{%ld}-IV-%ld] page 174",d1/6,(d-5)/6);
    1594          14 :               Ip->abe = 0; Ip->tor = 0;
    1595          14 :               Ip->neron = shallowconcat(groupH(d1/6), cyclic(3)); break;
    1596           0 :             default: pari_err_BUG("tame6 [bug50]");
    1597             :           }
    1598          28 :           break;
    1599           0 :         default: pari_err_BUG("tame6 [bug51]");
    1600             :       }
    1601         112 :       break;
    1602           0 :     default: pari_err_BUG("tame6 [bug52]");
    1603             :   }
    1604         287 :   return condp;
    1605             : }
    1606             : 
    1607             : static long
    1608         140 : tame_7(struct igusa *I, struct igusa_p *Ip)
    1609             : {
    1610         140 :   long condp = -1, d, D, d1, d2, n, dm, r, dk;
    1611         140 :   GEN val = Ip->val;
    1612             : 
    1613         140 :   dk = 3*(Ip->eps*val[3]-2*val[8]);
    1614         140 :   tame_567_init(I, Ip, dk, &d, &n, &dm, &r);
    1615         140 :   D = n * (Ip->eps*(val[6]-3*val[3])+val[8]) / Ip->eps;
    1616         140 :   d1 = minss(n * (val[7]-3*val[3]), D/2);
    1617         140 :   d2 = D - d1;
    1618             :   /* d1 <= d2 */
    1619         140 :   switch(n)
    1620             :   {
    1621          49 :     case 1: condp = 2;
    1622          49 :       Ip->type = stack_sprintf("[I{%ld}-I{%ld}-%ld] page 179",d1,d2,d);
    1623          49 :       Ip->abe = 0; Ip->tor = 2;
    1624          49 :       Ip->neron = dicyclic(d1,d2); break;
    1625          63 :     case 2:
    1626          63 :       if (odd(val[8]))
    1627             :       {
    1628          28 :         condp = 3;
    1629          28 :         Ip->type = stack_sprintf("[2I{%ld}-%ld] page 181",d1,d/2);
    1630          28 :         Ip->abe = 0; Ip->tor = 1;
    1631          28 :         Ip->neron = cyclic(d1);
    1632             :       }
    1633          35 :       else if (dm == 0)
    1634             :       {
    1635          21 :         condp = 4;
    1636          21 :         Ip->type = stack_sprintf("[I*{%ld}-I*{%ld}-%ld] page 180", d1/2,d2/2,(d-2)/2);
    1637          21 :         Ip->abe = 0; Ip->tor = 0;
    1638          21 :         Ip->neron = shallowconcat(groupH(d1/2),groupH(d2/2));
    1639             :       }
    1640             :       else
    1641             :       {
    1642             :         GEN H;
    1643          14 :         if (d1 != d2) return -1;
    1644           0 :         condp = 3; H = groupH(d1/2);
    1645           0 :         Ip->type = stack_sprintf("[I{%ld}-I*{%ld}-%ld] page 180", d1/2,d1/2,(d-1)/2);
    1646           0 :         Ip->abe = 0; Ip->tor = 1;
    1647           0 :         Ip->neron = shallowconcat(H, H);
    1648             :       }
    1649          49 :       break;
    1650          28 :     case 4: condp = 4;
    1651          28 :       Ip->type = stack_sprintf("[2I*{%ld}-%ld] page 181",d1/2,(d-2)/4);
    1652          28 :       Ip->abe = 0; Ip->tor = 0;
    1653          28 :       Ip->neron = groupH(d1/2); break;
    1654           0 :     default: pari_err_BUG("tame7 [bug55]");
    1655             :   }
    1656         126 :   return condp;
    1657             : }
    1658             : 
    1659             : static long labelm3(GEN polh, long t60, long alpha, long Dmin, struct igusa *I, struct igusa_p *Ip);
    1660             : static long
    1661        1533 : tame(GEN polh, long t60, long alpha, long Dmin, struct igusa *I, struct igusa_p *Ip)
    1662             : {
    1663             :   long d;
    1664        1533 :   Ip->tame = 1;
    1665        1533 :   switch(Ip->tt)
    1666             :   {
    1667          49 :     case 1: return tame_1(I,Ip);
    1668         175 :     case 2: return tame_2(I,Ip);
    1669          98 :     case 3: return tame_3(I,Ip);
    1670          98 :     case 4: return tame_4(I,Ip);
    1671         651 :     case 5: return tame_5(I,Ip);
    1672         322 :     case 6: d = tame_6(I,Ip); break;
    1673         140 :     default:d = tame_7(I,Ip); break;
    1674             :   }
    1675         462 :   if (d < 0) d = labelm3(polh,t60,alpha,Dmin,I,Ip); /* => tt=6 or 7 */
    1676         462 :   return d;
    1677             : }
    1678             : 
    1679             : /* maxc = maximum conductor valuation at p */
    1680             : static long
    1681         686 : get_maxc(GEN p)
    1682             : {
    1683         686 :   switch (itos_or_0(p))
    1684             :   {
    1685           0 :     case 2:  return 20; break;
    1686         301 :     case 3:  return 10; break;
    1687          14 :     case 5:  return 9; break;
    1688         371 :     default: return 4; break; /* p > 5 */
    1689             :   }
    1690             : }
    1691             : 
    1692             : /* p = 3 */
    1693             : static long
    1694          84 : quartic(GEN polh, long alpha, long Dmin, struct igusa_p *Ip)
    1695             : {
    1696          84 :   GEN val = Ip->val, p = Ip->p;
    1697          84 :   GEN polf = polymini_zi2(ZX_Z_mul(polh, powiu(p, alpha)));
    1698          84 :   long condp = -1, d, R, r1, beta;
    1699          84 :   r1 = polf[1];
    1700          84 :   beta = polf[2];
    1701          84 :   R = beta/2;
    1702          84 :   switch(Ip->tt)
    1703             :   {
    1704          70 :     case 1: case 5: d = 0;break;
    1705           0 :     case 3: d = val[6] - 5*val[3]/2;break;
    1706          14 :     case 7: d = val[6] - 3*val[3] + val[8]/Ip->eps;break;
    1707           0 :     default: pari_err_BUG("quartic [type choices]");
    1708             :              d = 0; /*LCOV_EXCL_LINE*/
    1709             :   }
    1710          84 :   switch(r1)
    1711             :   {
    1712          21 :     case 0:
    1713          21 :       if (d)
    1714             :       {
    1715           7 :         condp = 3;
    1716           7 :         Ip->type = stack_sprintf("[2I{%ld}-%ld] page 181",d,R);
    1717           7 :         Ip->abe = 0; Ip->tor = 1;
    1718           7 :         Ip->neron = cyclic(d);
    1719             :       }
    1720             :       else
    1721             :       {
    1722          14 :         condp = 2;
    1723          14 :         Ip->neron = cyclic(1);
    1724          14 :         Ip->abe = 1; Ip->tor = 0;
    1725          14 :         if (R) Ip->type = stack_sprintf("[2I{0}-%ld] page 159",R);
    1726           7 :         else   Ip->type = "[II] page 155";
    1727             :       }
    1728          21 :       break;
    1729          14 :     case 6: condp = 4;
    1730          14 :       Ip->type = stack_sprintf("[2I*{%ld}-%ld] pages 159, 181",d,R);
    1731          14 :       Ip->abe = 0; Ip->tor = 0;
    1732          14 :       Ip->neron = dicyclic(2,2); break;
    1733           7 :     case 3: condp = 4;
    1734           7 :       Ip->type = stack_sprintf("[2III-%ld] page 168",R);
    1735           7 :       Ip->abe = 0; Ip->tor = 0;
    1736           7 :       Ip->neron = cyclic(2); break;
    1737           7 :     case 9: condp = 4;
    1738           7 :       Ip->type = stack_sprintf("[2III*-%ld] page 168",R);
    1739           7 :       Ip->abe = 0; Ip->tor = 0;
    1740           7 :       Ip->neron = cyclic(2); break;
    1741           7 :     case 2: condp = Dmin-12*R-13;
    1742           7 :       Ip->type = stack_sprintf("[2II-%ld] page 162",R);
    1743           7 :       Ip->abe = 0; Ip->tor = 0;
    1744           7 :       Ip->neron = cyclic(1); break;
    1745          14 :     case 8: condp = Dmin-12*R-19;
    1746          14 :       Ip->type = stack_sprintf("[2IV*-%ld] page 165",R);
    1747          14 :       Ip->abe = 0; Ip->tor = 0;
    1748          14 :       Ip->neron = cyclic(3); break;
    1749           7 :     case 4: condp = Dmin-12*R-15;
    1750           7 :       Ip->type = stack_sprintf("[2IV-%ld] page 165",R);
    1751           7 :       Ip->abe = 0; Ip->tor = 0;
    1752           7 :       Ip->neron = cyclic(3); break;
    1753           7 :     case 10: condp = Dmin-12*R-21;
    1754           7 :       Ip->type = stack_sprintf("[2II*-%ld] page 163",R);
    1755           7 :       Ip->abe = 0; Ip->tor = 0;
    1756           7 :       Ip->neron = cyclic(1); break;
    1757           0 :     default: pari_err_BUG("quartic [type1]");
    1758             :   }
    1759          84 :   if (condp > get_maxc(p) || condp < 0) pari_err_BUG("quartic [conductor]");
    1760          84 :   return condp;
    1761             : }
    1762             : 
    1763             : static long
    1764         301 : litredtp(long alpha, long alpha1, long t60, long t60_1, GEN polh, GEN polh1,
    1765             :          long Dmin, long R, struct igusa *I, struct igusa_p *Ip)
    1766             : {
    1767         301 :   GEN val = Ip->val, p = Ip->p;
    1768         301 :   long condp = -1, indice, d, page;
    1769             : 
    1770         301 :   if ((Ip->r1 == 0||Ip->r1 == 6) && (Ip->r2 == 0||Ip->r2 == 6))
    1771             :   { /* (r1,r2) = (0,0), (0,6), (6,0) or (6,6) */
    1772         175 :     if (Ip->tt == 5)
    1773             :     {
    1774          21 :       switch(Ip->r1 + Ip->r2)
    1775             :       {
    1776           7 :       case 0: /* (0,0) */
    1777           7 :         condp = 0;
    1778           7 :         Ip->type = stack_sprintf("[I{0}-I{0}-%ld] page 158",R);
    1779           7 :         Ip->abe = 2; Ip->tor = 0;
    1780           7 :         Ip->neron = cyclic(1); break;
    1781           7 :       case 6: /* (0,6) or (6,0) */
    1782           7 :         condp = 2;
    1783           7 :         Ip->type = stack_sprintf("[I{0}-I*{0}-%ld] page 159",R);
    1784           7 :         Ip->abe = 1; Ip->tor = 0;
    1785           7 :         Ip->neron = dicyclic(2,2); break;
    1786           7 :       case 12: /* (6,6) */
    1787           7 :         condp = 4;
    1788           7 :         Ip->type = stack_sprintf("[I*{0}-I*{0}-%ld] page 158",R);
    1789           7 :         Ip->abe = 0; Ip->tor = 0;
    1790           7 :         Ip->neron = mkvecsmall4(2,2,2,2); break;
    1791             :       }
    1792          21 :       return condp;
    1793             :     }
    1794         154 :     if (Ip->r1 == Ip->r2) return tame(polh, t60, alpha, Dmin, I, Ip);
    1795          63 :     if (Ip->tt == 6)
    1796             :     {
    1797          42 :       d = val[6] - val[7] + val[8]/Ip->eps;
    1798          42 :       if (Ip->r1 && alpha1 == 0) polh1 = ZX_unscale_divpow(polh1, p, 3);
    1799          42 :       if (FpX_is_squarefree(FpX_red(polh1,p),p))
    1800          14 :       { indice = 0; condp = 3-Ip->r2/6; }
    1801             :       else
    1802          28 :       { indice = d; condp = 3-Ip->r1/6; }
    1803             :     }
    1804             :     else
    1805             :     { /* Ip->tt == 7 */
    1806             :       long d1;
    1807          21 :       d = val[6] - 3*val[3] + val[8]/Ip->eps;
    1808          21 :       if (t60_1 == 60) polh1 = ZX_unscale_divpow(polh1, p, 3);
    1809          21 :       d1 = minss(val[7]-3*val[3],d/2);
    1810          21 :       if (d == 2*d1) indice = d1;
    1811             :       else
    1812             :       {
    1813          21 :         indice = discpart(polh1,p,d1+1);
    1814          21 :         if (indice>= d1+1) indice = d-d1; else indice = d1;
    1815             :       }
    1816          21 :       condp = 3;
    1817             :     }
    1818          63 :     if (Ip->r1) indice = d - indice; /* (r1,r2) = (6,0) */
    1819          63 :     Ip->neron = shallowconcat(cyclic(indice),groupH(d-indice));
    1820          63 :     if (Ip->tt == 6)
    1821             :     {
    1822          42 :       if (indice==0) { page = 170; Ip->abe = 1; Ip->tor = 0; }
    1823          21 :       else           { page = 171; Ip->abe = 0; Ip->tor = 1; }
    1824          21 :     } else           { page = 180; Ip->abe = 0; Ip->tor = 1; }
    1825          63 :     Ip->type = stack_sprintf("[I{%ld}-I*{%ld}-%ld] page %ld",
    1826             :                              indice,d-indice,R, page);
    1827          63 :     return condp;
    1828             :   }
    1829         126 :   if (Ip->tt == 7) pari_err_BUG("litredtp [switch ri]");
    1830             :   {
    1831         126 :     struct red __S1, __S2, *S1 = &__S1, *S2 = &__S2;
    1832         126 :     long f1 = get_red(S1, Ip, polh1, p, alpha1, Ip->r1);
    1833         126 :     long f2 = get_red(S2, Ip, polh,  p, alpha,  Ip->r2);
    1834             :     /* reorder to normalize representation */
    1835         126 :     if (S1->tnum > S2->tnum || (S1->tnum == S2->tnum && f1 > f2))
    1836          56 :     { struct red *S = S1; S1 = S2; S2 = S; }
    1837         126 :     Ip->type = stack_sprintf("[%s-%s-%ld] pages %s", S1->t,S2->t, R, S1->pages);
    1838         126 :     Ip->neron = shallowconcat(S1->g, S2->g);
    1839         126 :     condp = Dmin - (f1 + f2) + ((R >= 0)? 2-12*R: 4);
    1840             :   }
    1841         126 :   if (condp > get_maxc(p)) pari_err_BUG("litredtp [conductor]");
    1842         126 :   return condp;
    1843             : }
    1844             : 
    1845             : static long
    1846         280 : labelm3(GEN h1, long t60_1, long alpha1, long Dmin, struct igusa *I, struct igusa_p *Ip)
    1847             : {
    1848         280 :   GEN h, pm, vs, val = Ip->val, p = Ip->p;
    1849             :   long alpha, t60, lambda, beta, R;
    1850             : 
    1851         280 :   pm = polymini(ZX_Z_mul(RgX_recip6(h1), powiu(p,alpha1)), p);
    1852         280 :   h  = gel(pm,1); vs = gel(pm,2);
    1853         280 :   lambda= vs[1];
    1854         280 :   t60   = vs[2];
    1855         280 :   alpha = vs[3];
    1856         280 :   beta  = vs[5];
    1857         280 :   if (lambda != 3) pari_err_BUG("labelm3 [lambda != 3]");
    1858         280 :   R = beta-(alpha1+alpha);
    1859         280 :   if (odd(R)) pari_err_BUG("labelm3 [R odd]");
    1860         280 :   R /= 2;
    1861         280 :   if (R <= -2) pari_err_BUG("labelm3 [R <= -2]");
    1862         280 :   if (val[8] % (2*Ip->eps)) pari_err_BUG("labelm3 [val(eps2)]");
    1863         280 :   if (R >= 0 && (alpha+alpha1) >= 1) pari_err_BUG("labelm3 [minimal equation]");
    1864         280 :   Ip->r1 = t60_1 / 10 + 6*alpha1;
    1865         280 :   Ip->r2 = t60 / 10 + 6*alpha;
    1866         280 :   return litredtp(alpha, alpha1, t60, t60_1, h, h1, Dmin, R, I, Ip);
    1867             : }
    1868             : 
    1869             : /* p = 3 */
    1870             : static long
    1871          21 : quadratic(GEN polh, long alpha, long Dmin, struct igusa *I, struct igusa_p *Ip)
    1872             : {
    1873          21 :   long alpha1 = alpha, beta, t6, R;
    1874          21 :   GEN vs = polymini_zi(ZX_Z_mul(polh, powiu(Ip->p,alpha)));
    1875          21 :   t6 = vs[1];
    1876          21 :   alpha = vs[2];
    1877          21 :   beta  = vs[3];
    1878          21 :   R = beta-alpha;
    1879          21 :   if (R >= 0 && alpha1)
    1880             :   {
    1881           0 :     Dmin -= 10;
    1882           0 :     if (DEBUGLEVEL)
    1883           0 :       err_printf("(Care: minimal discriminant over Z[i] smaller than over Z)\n");
    1884             :   }
    1885          21 :   Ip->r2 = Ip->r1 = t6 + 6*alpha;
    1886          21 :   return litredtp(alpha, alpha, t6*10, t6*10, polh, polh, Dmin, R, I, Ip);
    1887             : }
    1888             : 
    1889             : static long
    1890        2324 : genus2localred(struct igusa *I, struct igusa_p *Ip, GEN p, GEN polmini)
    1891             : {
    1892             :   GEN val, vs, polh, list, c1, c2, c3, c4, c5, c6, prod;
    1893             :   long i, vb5, vb6, d, Dmin, alpha, lambda, t60;
    1894        2324 :   long condp = -1, indice, vc6, mm, nb, dism;
    1895             : 
    1896        2324 :   stable_reduction(I, Ip, p);
    1897        2324 :   val = Ip->val; Dmin = val[6];
    1898        2324 :   if (Dmin == 0)
    1899             :   {
    1900          14 :     Ip->tame = 1;
    1901          14 :     Ip->type = "[I{0-0-0}] page 155";
    1902          14 :     Ip->abe = 2; Ip->tor = 0;
    1903          14 :     Ip->neron = cyclic(1); return 0;
    1904             :   }
    1905        2310 :   if (Dmin == 1)
    1906             :   {
    1907          14 :     Ip->type = "[I{1-0-0}] page 170";
    1908          14 :     Ip->abe = Ip->tor = 1;
    1909          14 :     Ip->neron = cyclic(1); return 1;
    1910             :   }
    1911        2296 :   if (Dmin == 2) switch(Ip->tt)
    1912             :   {
    1913           0 :     case 2:
    1914           0 :       Ip->type = "[I{2-0-0}] page 170";
    1915           0 :       Ip->abe = Ip->tor = 1;
    1916           0 :       Ip->neron = cyclic(2); return 1;
    1917           0 :     case 3:
    1918           0 :       Ip->type = "[I{1-1-0}] page 179";
    1919           0 :       Ip->abe = 0; Ip->tor = 2;
    1920           0 :       Ip->neron = cyclic(1); return 2;
    1921          14 :     case 5:
    1922          14 :       if (cmpis(p,3) <= 0) pari_err_BUG("genus2localred [tt 1]");
    1923          14 :       Ip->type = "[I{0}-II-0] page 159";
    1924          14 :       Ip->abe = 1; Ip->tor = 0;
    1925          14 :       Ip->neron = cyclic(1); return 2;
    1926           0 :     default: pari_err_BUG("genus2localred [tt 2]");
    1927             :   }
    1928        2282 :   if (absequaliu(p,2)) return -1;
    1929        2261 :   polh = gel(polmini,1); vs = gel(polmini,2);
    1930        2261 :   lambda = vs[1];
    1931        2261 :   t60    = vs[2];
    1932        2261 :   alpha  = vs[3];
    1933        2261 :   if (vs[4]) return equaliu(p,3)? quadratic(polh, alpha, Dmin, I, Ip):
    1934           0 :                                   tame(polh, t60, alpha, Dmin, I, Ip);
    1935        2240 :   if (!t60 && lambda<= 2)
    1936             :   {
    1937           7 :     if (Ip->tt >= 5) pari_err_BUG("genus2localred [tt 3]");
    1938           7 :     return tame(polh, t60, alpha, Dmin, I, Ip);
    1939             :   }
    1940        2233 :   if (Dmin == 3)
    1941             :   {
    1942           7 :     switch(Ip->tt)
    1943             :     {
    1944           0 :       case 2: return tame(polh, t60, alpha, Dmin, I, Ip);
    1945           0 :       case 3:
    1946           0 :         Ip->type = "[I{2-1-0}] page 179";
    1947           0 :         Ip->abe = 0; Ip->tor = 2;
    1948           0 :         Ip->neron = cyclic(2);
    1949           0 :         return 2;
    1950           7 :       case 4:
    1951           7 :         Ip->type = "[I{1-1-1}] page 182";
    1952           7 :         Ip->abe = 0; Ip->tor = 2;
    1953           7 :         Ip->neron = cyclic(3);
    1954           7 :         return 2;
    1955           0 :       case 5:
    1956           0 :         if (equaliu(p,3) && t60 != 30)
    1957           0 :           return labelm3(polh,t60,alpha,Dmin,I,Ip);
    1958           0 :         Ip->type = "[I{0}-III-0] page 161"; Ip->neron = cyclic(2);
    1959           0 :         Ip->abe = 1; Ip->tor = 0; return 2;
    1960           0 :       case 6:
    1961           0 :         if (equaliu(p,3)) pari_err_BUG("genus2localred [conductor]");
    1962           0 :         Ip->type = "[I{1}-II-0] page 172"; Ip->abe = 0; Ip->tor = 1; Ip->neron = cyclic(1); return 3;
    1963             :     }
    1964           0 :     pari_err_BUG("genus2localred [switch tt 4]");
    1965             :     return -1; /* LCOV_EXCL_LINE */
    1966             :   }
    1967        2226 :   switch(lambda)
    1968             :   {
    1969         595 :     case 0:
    1970         595 :       switch(t60+alpha)
    1971             :       {
    1972          14 :         case 10:
    1973          14 :           condp = Dmin-1;
    1974          14 :           Ip->type = "[V] page 156";
    1975          14 :           Ip->neron = cyclic(3); break;
    1976          14 :         case 11:
    1977          14 :           condp = Dmin-11;
    1978          14 :           Ip->type = "[V*] page 156";
    1979          14 :           Ip->neron = cyclic(3); break;
    1980          14 :         case 12:
    1981          14 :           condp = Dmin-2;
    1982          14 :           Ip->type = "[IX-2] page 157";
    1983          14 :           Ip->neron = cyclic(5); break;
    1984          21 :         case 13:
    1985          21 :           condp = Dmin-12;
    1986          21 :           Ip->type = "[VIII-4] page 157";
    1987          21 :           Ip->neron = cyclic(1); break;
    1988          14 :         case 24:
    1989          14 :           condp = Dmin-8;
    1990          14 :           Ip->type = "[IX-4] page 158";
    1991          14 :           Ip->neron = cyclic(5);
    1992          14 :           break;
    1993          28 :         case 15: case 16:
    1994          28 :           if (Ip->tt>= 5) pari_err_BUG("genus2localred [tt 6]");
    1995          28 :           return tame(polh, t60, alpha, Dmin, I, Ip);
    1996         182 :         case 20: case 21:
    1997             :           {
    1998             :             GEN b0, b1, b2, b3, b4, b5, b6, b02, b03, b04, b05;
    1999         182 :             RgX_to_06(polh, &b0,&b1,&b2,&b3,&b4,&b5,&b6);
    2000         182 :             vb5 = myval(b5,p);
    2001         182 :             vb6 = myval(b6,p);
    2002         182 :             if (vb6 >= 3)
    2003             :             {
    2004          28 :               if (vb5 < 2) pari_err_BUG("genus2localred [red1]");
    2005          28 :               if (vb5 >= 3)
    2006             :               {
    2007          14 :                 condp = Dmin-8;
    2008          14 :                 Ip->type = "[II*-IV-(-1)] page 164";
    2009          14 :                 Ip->neron = cyclic(3);
    2010             :               }
    2011             :               else
    2012             :               {
    2013          14 :                 condp = Dmin-7;
    2014          14 :                 Ip->type = "[IV-III*-(-1)] page 167";
    2015          14 :                 Ip->neron = cyclic(6);
    2016             :               }
    2017          28 :               break;
    2018             :             }
    2019         154 :             if (dvdii(b0,p)) pari_err_BUG("genus2localred [b0]");
    2020         154 :             b02 = gsqr(b0);
    2021         154 :             b03 = gmul(b02, b0);
    2022         154 :             b04 = gmul(b03, b0);
    2023         154 :             b05 = gmul(b04, b0);
    2024         154 :             c1 = gmul2n(b1,-1);
    2025         154 :             c2 = gmul2n(gsub(gmul(b0,b2), gsqr(c1)),-1);
    2026         154 :             c3 = gmul2n(gsub(gmul(b02,b3), gmul2n(gmul(c1,c2),1)),-1);
    2027         154 :             c4 = gsub(gmul(b03,b4), gadd(gmul2n(gmul(c1,c3),1),gsqr(c2)));
    2028         154 :             c5 = gsub(gmul(b04,b5), gmul2n(gmul(c2,c3),1));
    2029         154 :             c6 = gsub(gmul(b05,b6), gsqr(c3));
    2030             :             /* b0^5*H(x/b0) = (x^3+c1*x^2+c2*x+c3)^2+c4*x^2+c5*x+c6 */
    2031         154 :             vc6 = myval(c6,p);
    2032         154 :             if (vc6 == 2)
    2033             :             {
    2034          14 :               if (alpha)
    2035             :               {
    2036           0 :                 condp = Dmin-16;
    2037           0 :                 Ip->type = "[IV] page 155";
    2038           0 :                 Ip->neron = cyclic(1);
    2039             :               }
    2040             :               else
    2041             :               {
    2042          14 :                 condp = Dmin-6;
    2043          14 :                 Ip->type = "[III] page 155";
    2044          14 :                 Ip->neron = dicyclic(3,3);
    2045             :               }
    2046             :             }
    2047             :             else
    2048             :             {
    2049         140 :               if (myval(c3,p) > 1) pari_err_BUG("genus2localred [c3]");
    2050         140 :               mm = min3(3*myval(c4,p)-4, 3*myval(c5,p)-5, 3*vc6-6);
    2051         140 :               if (alpha)
    2052             :               {
    2053          56 :                 condp = Dmin-mm-16;
    2054          56 :                 Ip->type = stack_sprintf("[III*{%ld}] page 184", mm);
    2055          56 :                 Ip->neron = cyclic(1);
    2056             :               }
    2057             :               else
    2058             :               {
    2059          84 :                 condp = Dmin-mm-6;
    2060          84 :                 Ip->type = stack_sprintf("[III{%ld}] page 184", mm);
    2061          84 :                 Ip->neron = (mm%3)? cyclic(9): dicyclic(3,3);
    2062             :               }
    2063             :             }
    2064             :           }
    2065         154 :           break;
    2066         308 :         case 30:
    2067         392 :           return equaliu(p,3)? quartic(polh, alpha, Dmin, Ip)
    2068         392 :                              : tame(polh, t60, alpha, Dmin, I, Ip);
    2069           0 :         default: pari_err_BUG("genus2localred [red2]");
    2070             :       }
    2071         259 :       break;
    2072         210 :     case 1:
    2073         210 :       switch(t60+alpha)
    2074             :       {
    2075          14 :         case 12:
    2076          14 :           condp = Dmin;
    2077          14 :           Ip->type = "[VIII-1] page 156";
    2078          14 :           Ip->neron = cyclic(1); break;
    2079          14 :         case 13:
    2080          14 :           condp = Dmin-10;
    2081          14 :           Ip->type = "[IX-3] page 157";
    2082          14 :           Ip->neron = cyclic(5); break;
    2083          14 :         case 24:
    2084          14 :           condp = Dmin-4;
    2085          14 :           Ip->type = "[IX-1] page 157";
    2086          14 :           Ip->neron = cyclic(5); break;
    2087          14 :         case 25:
    2088          14 :           condp = Dmin-14;
    2089          14 :           Ip->type = "[VIII-3] page 157";
    2090          14 :           Ip->neron = cyclic(1); break;
    2091          14 :         case 36:
    2092          14 :           condp = Dmin-8;
    2093          14 :           Ip->type = "[VIII-2] page 157";
    2094          14 :           Ip->neron = cyclic(1); break;
    2095          28 :         case 15:
    2096          28 :           condp = Dmin-1;
    2097          28 :           Ip->type = "[VII] page 156";
    2098          28 :           Ip->neron = cyclic(2); break;
    2099          14 :         case 16:
    2100          14 :           condp = Dmin-11;
    2101          14 :           Ip->type = "[VII*] page 156";
    2102          14 :           Ip->neron = cyclic(2); break;
    2103          21 :         case 20:
    2104          21 :           if (cmpis(p,3))
    2105             :           {
    2106          14 :             d = 6*val[6]-5*val[7]-2;
    2107          14 :             if (d%6) pari_err_BUG("genus2localred [index]");
    2108          14 :             dism = (d/6);
    2109             :           }
    2110             :           else
    2111             :           {
    2112           7 :             list = padicfactors(polh,p,Dmin-5);
    2113           7 :             nb = lg(list);
    2114           7 :             prod = pol_1(varn(polh));
    2115          21 :             for(i = 1;i<nb;i++)
    2116             :             {
    2117          14 :               GEN c = gel(list,i);
    2118          14 :               if (valp(gel(c,2)) && degpol(c)<= 2) prod = RgX_mul(prod,c);
    2119             :             }
    2120           7 :             if (degpol(prod) > 2) pari_err_BUG("genus2localred [padicfactors]");
    2121           7 :             dism = valp(RgX_disc(prod)) - 1;
    2122             :           }
    2123          21 :           condp = Dmin-dism-3;
    2124          21 :           Ip->type = stack_sprintf("[II-II*{%ld}] page 176", dism);
    2125          21 :           Ip->neron = groupH(dism+1); break;
    2126          21 :         case 21:
    2127          21 :           vb6 = myval(RgX_coeff(polh,0),p);
    2128          21 :           if (vb6<2) pari_err_BUG("genus2localred [red3]");
    2129          21 :           condp = Dmin-14;
    2130          21 :           Ip->type = "[IV*-II{0}] page 175";
    2131          21 :           Ip->abe = 0; Ip->tor = 1;
    2132          21 :           Ip->neron = cyclic(1); break;
    2133          56 :         case 30:
    2134          56 :           vb5 = myval(RgX_coeff(polh,1),p);
    2135          56 :           if (vb5 == 2)
    2136             :           {
    2137          42 :             if (Ip->tt >= 5) pari_err_BUG("genus2localred [tt 6]");
    2138          42 :             return tame(polh, t60, alpha, Dmin, I, Ip);
    2139             :           }
    2140          14 :           condp = Dmin-7;
    2141          14 :           Ip->type = "[II*-III-(-1)] page 167";
    2142          14 :           Ip->neron = cyclic(2); break;
    2143             :       }
    2144         168 :       break;
    2145         238 :     case 2:
    2146         238 :       if (ugcd(t60, 60) == 15) /* denom(theta) = 4 */
    2147             :       {
    2148          49 :         if (Ip->tt>4) pari_err_BUG("genus2localred [tt 5]");
    2149          49 :         return tame(polh, t60, alpha, Dmin, I, Ip);
    2150             :       }
    2151         189 :       if (!equaliu(p,3) && ugcd(t60, 60) == 20) /* denom(theta) = 3 */
    2152          42 :         return tame(polh, t60, alpha, Dmin, I, Ip);
    2153         147 :       list = padicfactors(polh,p,Dmin-10*alpha);
    2154         147 :       nb = lg(list); prod = pol_1(varn(polh));
    2155         490 :       for(i = 1;i<nb;i++)
    2156             :       {
    2157         343 :         GEN c = gel(list,i);
    2158         343 :         if (!valp(gel(c,2))) prod = RgX_mul(prod,c);
    2159             :       }
    2160         147 :       switch(degpol(prod))
    2161             :       {
    2162             :         GEN e0, e1, e2;
    2163           0 :         case 0:
    2164           0 :           dism = 0; break;
    2165           7 :         case 1:
    2166           7 :           e1 = gel(prod,3);
    2167           7 :           dism = 2*valp(e1); break;
    2168         140 :         case 2:
    2169         140 :           e0 = gel(prod,2);
    2170         140 :           e1 = gel(prod,3);
    2171         140 :           e2 = gel(prod,4);
    2172         140 :           dism = valp(gsub(gsqr(e1),gmul2n(gmul(e0,e2),2))); break;
    2173           0 :         default:
    2174           0 :           pari_err_BUG("genus2localred [padicfactors 2]");
    2175           0 :           dism = 0;
    2176             :       }
    2177         147 :       switch(t60/5+alpha-4)
    2178             :       {
    2179          14 :         case 0:
    2180          14 :           condp = Dmin-dism-1;
    2181          14 :           Ip->type = stack_sprintf("[IV-II{%ld}] page 175", dism);
    2182          14 :           Ip->abe = 0; Ip->tor = 1;
    2183          14 :           Ip->neron = cyclic(3*dism+2); break;
    2184           7 :         case 1:
    2185           7 :           condp = Dmin-dism-10;
    2186           7 :           Ip->type = stack_sprintf("[II*-II*{%ld}] page 176",dism);
    2187           7 :           Ip->neron = groupH(dism+1); break;
    2188         119 :         case 2: case 3:
    2189         119 :           if (myval(RgX_coeff(polh,0),p) == 2)
    2190             :           {
    2191          98 :             if (Ip->tt>4) pari_err_BUG("genus2localred [tt 5]");
    2192          98 :             return tame(polh, t60, alpha, Dmin, I, Ip);
    2193             :           }
    2194          21 :           dism++;
    2195          21 :           indice = val[6]-(5*val[3]/2)-dism;
    2196          21 :           condp = Dmin-dism-indice-2;
    2197          21 :           Ip->type = stack_sprintf("[II{%ld-%ld}] page 182", dism,indice);
    2198          21 :           Ip->abe = 0; Ip->tor = 1;
    2199          21 :           Ip->neron = both_odd(dism,indice)? dicyclic(2,2*dism): cyclic(4*dism);
    2200          21 :           break;
    2201           7 :         case 4:
    2202           7 :           condp = Dmin-dism-5;
    2203           7 :           Ip->type = stack_sprintf("[IV*-II{%ld}] page 175",dism+1);
    2204           7 :           Ip->abe = 0; Ip->tor = 1;
    2205           7 :           Ip->neron = cyclic(3*dism+4); break;
    2206             :       }
    2207          49 :       break;
    2208        1183 :     case 3:
    2209        1183 :       if (!equaliu(p,3) || Ip->tt <= 4)
    2210         952 :         return tame(polh, t60, alpha, Dmin, I, Ip);
    2211         231 :       return labelm3(polh,t60,alpha,Dmin,I,Ip); /* p = 3 */
    2212           0 :     default: pari_err_BUG("genus2localred [switch lambda]");
    2213             :   }
    2214         476 :   if (condp < 2 || condp > get_maxc(p))
    2215           0 :     pari_err_BUG("genus2localred [conductor]");
    2216         476 :   return condp;
    2217             : }
    2218             : 
    2219             : static GEN
    2220        2282 : hyperellintegralmodel(GEN PQ)
    2221             : {
    2222             :   GEN D;
    2223        2282 :   PQ = Q_remove_denom(PQ, &D);
    2224        2282 :   if (!D) return PQ;
    2225          14 :   if (typ(PQ)==t_POL) return gmul(PQ,D);
    2226           0 :   if (typ(PQ) == t_VEC && lg(PQ) == 3)
    2227           0 :     return mkvec2(gmul(gel(PQ,1),D), gel(PQ,2));
    2228           0 :   pari_err_TYPE("hyperellintegralmodel",PQ);
    2229             :   return NULL; /* LCOV_EXCL_LINE */
    2230             : }
    2231             : 
    2232             : /* P,Q are ZX, study Y^2 + Q(X) Y = P(X) */
    2233             : GEN
    2234        2282 : genus2red(GEN PQ, GEN p)
    2235             : {
    2236        2282 :   pari_sp av = avma;
    2237             :   struct igusa I;
    2238             :   GEN P, Q;
    2239             :   GEN j22, j42, j2j6, a0,a1,a2,a3,a4,a5,a6, V,polr,facto,factp, vecmini, cond;
    2240             :   long i, l, dd;
    2241        2282 :   PQ = hyperellminimalmodel(hyperellintegralmodel(PQ), NULL, p ? mkvec(p): p);
    2242        2282 :   P = gel(PQ,1);
    2243        2282 :   Q = gel(PQ,2);
    2244        2282 :   if (p && typ(p) != t_INT) pari_err_TYPE("genus2red", p);
    2245             : 
    2246        2282 :   polr = ZX_add(ZX_sqr(Q), gmul2n(P,2)); /* ZX */
    2247        2282 :   switch(degpol(polr))
    2248             :   {
    2249        2282 :     case 5: case 6: break;
    2250           0 :     default: pari_err_DOMAIN("genus2red","genus","!=", gen_2,mkvec2(P,Q));
    2251             :   }
    2252             : 
    2253        2282 :   RgX_to_03(polr, &a0,&a1,&a2,&a3);
    2254        2282 :   I.j10 = !signe(a0)? mulii(sqri(a1), ZX_disc(polr)): ZX_disc(polr);
    2255        2282 :   if (!signe(I.j10))
    2256           0 :     pari_err_DOMAIN("genus2red","genus","<",gen_2,mkvec2(P,Q));
    2257        2282 :   I.j10 = gmul2n(I.j10, -12); /* t_INT */
    2258             : 
    2259        2282 :   if (p == NULL)
    2260             :   {
    2261          49 :     facto = absZ_factor(I.j10);
    2262          49 :     factp = gel(facto,1);
    2263             :   }
    2264             :   else
    2265             :   {
    2266        2233 :     factp = mkcol(p);
    2267        2233 :     facto = mkmat2(factp, mkcol(gen_1));
    2268             :   }
    2269        2282 :   l = lg(factp);
    2270        2282 :   vecmini = cgetg(l, t_COL);
    2271        4606 :   for(i = 1; i<l; i++)
    2272             :   {
    2273        2324 :     GEN l = gel(factp,i), pm;
    2274        2324 :     if (i == 1 && absequaliu(l, 2)) { gel(vecmini,1) = gen_0; continue; }
    2275        2303 :     gel(vecmini,i) = pm = polymini(polr, l);
    2276        2303 :     polr = ZX_Q_mul(gel(pm,1), powiu(l, gel(pm,2)[3]));
    2277             :   }
    2278        2282 :   RgX_to_06(polr, &a0,&a1,&a2,&a3,&a4,&a5,&a6);
    2279        2282 :   I.j10 = !signe(a0)? mulii(sqri(a1), ZX_disc(polr)): ZX_disc(polr);
    2280        2282 :   I.j10 = gmul2n(I.j10,-12);
    2281             : 
    2282        2282 :   I.a0 = a0;
    2283        2282 :   I.A2 = apol2(a0,a1,a2);
    2284        2282 :   I.A3 = apol3(a0,a1,a2,a3);
    2285        2282 :   I.A5 = apol5(a0,a1,a2,a3,a4,a5);
    2286        2282 :   I.B2 = bpol2(a0,a1,a2,a3,a4);
    2287             : 
    2288        2282 :   I.j2 = igusaj2(a0,a1,a2,a3,a4,a5,a6);
    2289        2282 :   I.j4 = igusaj4(a0,a1,a2,a3,a4,a5,a6);
    2290        2282 :   I.i4 = gsub(gsqr(I.j2), gmulsg(24,I.j4));
    2291        2282 :   I.j6 = igusaj6(a0,a1,a2,a3,a4,a5,a6);
    2292        2282 :   j42 = gsqr(I.j4);
    2293        2282 :   j22 = gsqr(I.j2);
    2294        2282 :   j2j6 = gmul(I.j2,I.j6);
    2295        2282 :   I.j8 = gmul2n(gsub(j2j6,j42), -2);
    2296        2282 :   I.i12= gmul2n(gsub(gadd(gmul(j22,j42),gmulsg(36,gmul(j2j6,I.j4))),
    2297             :                      gadd(gadd(gmulsg(32,gmul(j42,I.j4)),gmul(j2j6,j22)),gmulsg(108,gsqr(I.j6)))),-2);
    2298             : 
    2299        4606 :   for(i = 1; i < l; i++)
    2300        2324 :     gcoeff(facto,i,2) = stoi(Q_pval(I.j10, gel(factp,i)));
    2301        2282 :   dd = ZX_pval(polr,gen_2) & (~1); /* = 2 floor(val/2) */
    2302        2282 :   polr = gmul2n(polr, -dd);
    2303             : 
    2304        2282 :   V = cgetg(l, t_VEC);
    2305        4606 :   for (i = 1; i < l; i++)
    2306             :   {
    2307        2324 :     GEN q = gel(factp,i), red, N = NULL;
    2308             :     struct igusa_p Ip;
    2309        2324 :     long f = genus2localred(&I, &Ip, q, gel(vecmini,i));
    2310        2324 :     gcoeff(facto,i,2) = stoi(f);
    2311        2324 :     if (Ip.tame) Ip.type = stack_strcat("(tame) ", Ip.type);
    2312        2324 :     if (f >= 0)
    2313        2303 :       N = zv_snf(Ip.neron);
    2314        2324 :     if (DEBUGLEVEL)
    2315             :     {
    2316           0 :       if (!p) err_printf("p = %Ps\n", q);
    2317           0 :       err_printf("(potential) stable reduction: %Ps\n", Ip.stable);
    2318           0 :       if (f >= 0) {
    2319           0 :         err_printf("reduction at p: %s, %Ps", Ip.type, N);
    2320           0 :         err_printf(", f = %ld\n", f);
    2321             :       }
    2322             :     }
    2323        2324 :     red = f >= 0? mkvec2(strtoGENstr(Ip.type), N): cgetg(1, t_VEC);
    2324        2324 :     gel(V, i) = mkvec4(q, Ip.stable, red, mkvecsmall3(Ip.abe,Ip.tor,2-(Ip.tor+Ip.abe)));
    2325             :   }
    2326        2282 :   if (p) V = gel(V,1);
    2327        2282 :   cond = factorback(facto);
    2328             :   /* remove denominator 2 coming from f = -1 in genuslocalred(, p = 2) */
    2329        2282 :   if (typ(cond) != t_INT) cond = gel(cond,1);
    2330        2282 :   return gerepilecopy(av, mkvec4(cond, facto, PQ, V));
    2331             : }

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