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 - basemath - buch2.c (source / functions) Hit Total Coverage
Test: PARI/GP v2.18.1 lcov report (development 30590-f14e077362) Lines: 2213 2528 87.5 %
Date: 2026-01-02 09:20:44 Functions: 159 176 90.3 %
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */
      14             : #include "pari.h"
      15             : #include "paripriv.h"
      16             : 
      17             : #define DEBUGLEVEL DEBUGLEVEL_bnf
      18             : 
      19             : /*******************************************************************/
      20             : /*                                                                 */
      21             : /*         CLASS GROUP AND REGULATOR (McCURLEY, BUCHMANN)          */
      22             : /*                    GENERAL NUMBER FIELDS                        */
      23             : /*                                                                 */
      24             : /*******************************************************************/
      25             : /* get_random_ideal */
      26             : static const long RANDOM_BITS = 4;
      27             : /* Buchall */
      28             : static const long RELSUP = 5;
      29             : static const long FAIL_DIVISOR = 32;
      30             : static const long MINFAIL = 10;
      31             : /* small_norm */
      32             : static const long BNF_RELPID = 4;
      33             : static const long MAXTRY_FACT = 500;
      34             : /* rnd_rel */
      35             : static const long RND_REL_RELPID = 1;
      36             : /* random relations */
      37             : static const long MINSFB = 3;
      38             : static const long SFB_MAX = 3;
      39             : static const long DEPSIZESFBMULT = 16;
      40             : static const long DEPSFBDIV = 10;
      41             : /* add_rel_i */
      42             : static const ulong mod_p = 27449UL;
      43             : /* be_honest */
      44             : static const long maxtry_HONEST = 50;
      45             : 
      46             : typedef struct FACT {
      47             :     long pr, ex;
      48             : } FACT;
      49             : 
      50             : typedef struct subFB_t {
      51             :   GEN subFB;
      52             :   struct subFB_t *old;
      53             : } subFB_t;
      54             : 
      55             : /* a factor base contains only noninert primes
      56             :  * KC = # of P in factor base (p <= n, NP <= n2)
      57             :  * KC2= # of P assumed to generate class group (NP <= n2)
      58             :  *
      59             :  * KCZ = # of rational primes under ideals counted by KC
      60             :  * KCZ2= same for KC2 */
      61             : 
      62             : typedef struct FB_t {
      63             :   GEN FB; /* FB[i] = i-th rational prime used in factor base */
      64             :   GEN LP; /* vector of all prime ideals in FB, by increasing norm */
      65             :   GEN LV; /* LV[p] = vector of P|p, NP <= n2
      66             :             * isclone() is set for LV[p] iff all P|p are in FB
      67             :             * LV[i], i not prime or i > n2, is undefined! */
      68             :   GEN iLP; /* iLP[p] = i such that LV[p] = [LP[i],...] */
      69             :   GEN L_jid; /* indexes of "useful" prime ideals for rnd_rel */
      70             :   long KC, KCZ, KCZ2;
      71             :   GEN prodZ; /* product of the primes in KCZ*/
      72             :   GEN subFB; /* LP o subFB =  part of FB used to build random relations */
      73             :   int sfb_chg; /* need to change subFB ? */
      74             :   GEN perm; /* permutation of LP used to represent relations [updated by
      75             :                hnfspec/hnfadd: dense rows come first] */
      76             :   GEN idealperm; /* permutation of ideals under field automorphisms */
      77             :   GEN minidx; /* minidx[i] min ideal in orbit of LP[i] under field autom */
      78             :   subFB_t *allsubFB; /* all subFB's used */
      79             :   GEN embperm; /* permutations of the complex embeddings */
      80             :   long MAXDEPSIZESFB; /* # trials before increasing subFB */
      81             :   long MAXDEPSFB; /* MAXDEPSIZESFB / DEPSFBDIV, # trials befor rotating subFB */
      82             :   double ballvol;
      83             : } FB_t;
      84             : 
      85             : enum { sfb_CHANGE = 1, sfb_INCREASE = 2 };
      86             : 
      87             : typedef struct REL_t {
      88             :   GEN R; /* relation vector as t_VECSMALL; clone */
      89             :   long nz; /* index of first nonzero elt in R (hash) */
      90             :   GEN m; /* pseudo-minimum yielding the relation; clone */
      91             :   long relorig; /* relation this one is an image of */
      92             :   long relaut; /* automorphim used to compute this relation from the original */
      93             :   GEN emb; /* archimedean embeddings */
      94             :   GEN junk[2]; /*make sure sizeof(struct) is a power of two.*/
      95             : } REL_t;
      96             : 
      97             : typedef struct RELCACHE_t {
      98             :   REL_t *chk; /* last checkpoint */
      99             :   REL_t *base; /* first rel found */
     100             :   REL_t *last; /* last rel found so far */
     101             :   REL_t *end; /* target for last relation. base <= last <= end */
     102             :   size_t len; /* number of rels pre-allocated in base */
     103             :   long relsup; /* how many linearly dependent relations we allow */
     104             :   GEN basis; /* mod p basis (generating family actually) */
     105             :   ulong missing; /* missing vectors in generating family above */
     106             : } RELCACHE_t;
     107             : 
     108             : typedef struct FP_t {
     109             :   double **q, *v, *y, *z;
     110             :   GEN x;
     111             : } FP_t;
     112             : 
     113             : static void
     114           0 : wr_rel(GEN e)
     115             : {
     116           0 :   long i, l = lg(e);
     117           0 :   for (i = 1; i < l; i++)
     118           0 :     if (e[i]) err_printf("%ld^%ld ",i,e[i]);
     119           0 : }
     120             : static void
     121           0 : dbg_newrel(RELCACHE_t *cache)
     122             : {
     123           0 :   if (DEBUGLEVEL > 1)
     124             :   {
     125           0 :     err_printf("\n++++ cglob = %ld\nrel = ", cache->last - cache->base);
     126           0 :     wr_rel(cache->last->R);
     127           0 :     err_printf("\n");
     128             :   }
     129             :   else
     130           0 :     err_printf("%ld ", cache->last - cache->base);
     131           0 : }
     132             : 
     133             : static void
     134       64074 : delete_cache(RELCACHE_t *M)
     135             : {
     136             :   REL_t *rel;
     137     1057370 :   for (rel = M->base+1; rel <= M->last; rel++)
     138             :   {
     139      993295 :     gunclone(rel->R);
     140      993294 :     if (rel->m) gunclone(rel->m);
     141             :   }
     142       64075 :   pari_free((void*)M->base); M->base = NULL;
     143       64074 : }
     144             : 
     145             : static void
     146       66251 : delete_FB(FB_t *F)
     147             : {
     148             :   subFB_t *s, *sold;
     149      133258 :   for (s = F->allsubFB; s; s = sold) { sold = s->old; pari_free(s); }
     150       66251 :   gunclone(F->minidx);
     151       66251 :   gunclone(F->idealperm);
     152       66251 : }
     153             : 
     154             : static void
     155       64072 : reallocate(RELCACHE_t *M, long len)
     156             : {
     157       64072 :   M->len = len;
     158       64072 :   if (!M->base)
     159       64074 :     M->base = (REL_t*)pari_malloc((len+1) * sizeof(REL_t));
     160             :   else
     161             :   {
     162           0 :     size_t l = M->last - M->base, c = M->chk - M->base, e = M->end - M->base;
     163           0 :     pari_realloc_ip((void**)&M->base, (len+1) * sizeof(REL_t));
     164           0 :     M->last = M->base + l;
     165           0 :     M->chk  = M->base + c;
     166           0 :     M->end  = M->base + e;
     167             :   }
     168       64074 : }
     169             : 
     170             : #define pr_get_smallp(pr) gel(pr,1)[2]
     171             : 
     172             : /* don't take P|p all other Q|p are already there */
     173             : static int
     174      307568 : bad_subFB(FB_t *F, long t)
     175             : {
     176      307568 :   GEN LP, P = gel(F->LP,t);
     177      307568 :   long p = pr_get_smallp(P);
     178      307568 :   LP = gel(F->LV,p);
     179      307568 :   return (isclone(LP) && t == F->iLP[p] + lg(LP)-1);
     180             : }
     181             : 
     182             : static void
     183       67007 : assign_subFB(FB_t *F, GEN yes, long iyes)
     184             : {
     185       67007 :   long i, lv = sizeof(subFB_t) + iyes*sizeof(long); /* for struct + GEN */
     186       67007 :   subFB_t *s = (subFB_t *)pari_malloc(lv);
     187       67007 :   s->subFB = (GEN)&s[1];
     188       67007 :   s->old = F->allsubFB; F->allsubFB = s;
     189      288827 :   for (i = 0; i < iyes; i++) s->subFB[i] = yes[i];
     190       67007 :   F->subFB = s->subFB;
     191       67007 :   F->MAXDEPSIZESFB = (iyes-1) * DEPSIZESFBMULT;
     192       67007 :   F->MAXDEPSFB = F->MAXDEPSIZESFB / DEPSFBDIV;
     193       67007 : }
     194             : 
     195             : /* Determine the permutation of the ideals made by each field automorphism */
     196             : static GEN
     197       66250 : FB_aut_perm(FB_t *F, GEN auts, GEN cyclic)
     198             : {
     199       66250 :   long i, j, m, KC = F->KC, nauts = lg(auts)-1;
     200       66250 :   GEN minidx, perm = zero_Flm_copy(KC, nauts);
     201             : 
     202       66249 :   if (!nauts) { F->minidx = gclone(identity_zv(KC)); return cgetg(1,t_MAT); }
     203       41959 :   minidx = zero_Flv(KC);
     204       91730 :   for (m = 1; m < lg(cyclic); m++)
     205             :   {
     206       49771 :     GEN thiscyc = gel(cyclic, m);
     207       49771 :     long k0 = thiscyc[1];
     208       49771 :     GEN aut = gel(auts, k0), permk0 = gel(perm, k0), ppermk;
     209       49771 :     i = 1;
     210      214408 :     while (i <= KC)
     211             :     {
     212      164637 :       pari_sp av2 = avma;
     213      164637 :       GEN seen = zero_Flv(KC), P = gel(F->LP, i);
     214      164637 :       long imin = i, p, f, l;
     215      164637 :       p = pr_get_smallp(P);
     216      164637 :       f = pr_get_f(P);
     217             :       do
     218             :       {
     219      482847 :         if (++i > KC) break;
     220      433075 :         P = gel(F->LP, i);
     221             :       }
     222      433075 :       while (p == pr_get_smallp(P) && f == pr_get_f(P));
     223      647471 :       for (j = imin; j < i; j++)
     224             :       {
     225      482845 :         GEN img = ZM_ZC_mul(aut, pr_get_gen(gel(F->LP, j)));
     226     1672180 :         for (l = imin; l < i; l++)
     227     1672180 :           if (!seen[l] && ZC_prdvd(img, gel(F->LP, l)))
     228             :           {
     229      482833 :             seen[l] = 1; permk0[j] = l; break;
     230             :           }
     231             :       }
     232      164626 :       set_avma(av2);
     233             :     }
     234       68955 :     for (ppermk = permk0, i = 2; i < lg(thiscyc); i++)
     235             :     {
     236       19184 :       GEN permk = gel(perm, thiscyc[i]);
     237      384169 :       for (j = 1; j <= KC; j++) permk[j] = permk0[ppermk[j]];
     238       19184 :       ppermk = permk;
     239             :     }
     240             :   }
     241      311048 :   for (j = 1; j <= KC; j++)
     242             :   {
     243      269089 :     if (minidx[j]) continue;
     244      129399 :     minidx[j] = j;
     245      361849 :     for (i = 1; i <= nauts; i++) minidx[coeff(perm, j, i)] = j;
     246             :   }
     247       41959 :   F->minidx = gclone(minidx); return perm;
     248             : }
     249             : 
     250             : /* set subFB.
     251             :  * Fill F->perm (if != NULL): primes ideals sorted by increasing norm (except
     252             :  * the ones in subFB come first [dense rows for hnfspec]) */
     253             : static void
     254       66247 : subFBgen(FB_t *F, GEN auts, GEN cyclic, double PROD, long minsFB)
     255             : {
     256             :   GEN y, perm, yes, no;
     257       66247 :   long i, j, k, iyes, ino, lv = F->KC + 1;
     258             :   double prod;
     259             :   pari_sp av;
     260             : 
     261       66247 :   F->LP   = cgetg(lv, t_VEC);
     262       66247 :   F->L_jid = F->perm = cgetg(lv, t_VECSMALL);
     263       66247 :   av = avma;
     264       66247 :   y = cgetg(lv,t_COL); /* Norm P */
     265      313405 :   for (k=0, i=1; i <= F->KCZ; i++)
     266             :   {
     267      247155 :     GEN LP = gel(F->LV,F->FB[i]);
     268      247155 :     long l = lg(LP);
     269      714684 :     for (j = 1; j < l; j++)
     270             :     {
     271      467526 :       GEN P = gel(LP,j);
     272      467526 :       k++;
     273      467526 :       gel(y,k) = pr_norm(P);
     274      467529 :       gel(F->LP,k) = P;
     275             :     }
     276             :   }
     277             :   /* perm sorts LP by increasing norm */
     278       66250 :   perm = indexsort(y);
     279       66250 :   no  = cgetg(lv, t_VECSMALL); ino  = 1;
     280       66250 :   yes = cgetg(lv, t_VECSMALL); iyes = 1;
     281       66250 :   prod = 1.0;
     282      303468 :   for (i = 1; i < lv; i++)
     283             :   {
     284      273494 :     long t = perm[i];
     285      273494 :     if (bad_subFB(F, t)) { no[ino++] = t; continue; }
     286             : 
     287      153012 :     yes[iyes++] = t;
     288      153012 :     prod *= (double)itos(gel(y,t));
     289      153012 :     if (iyes > minsFB && prod > PROD) break;
     290             :   }
     291       66250 :   setlg(yes, iyes);
     292      219259 :   for (j=1; j<iyes; j++)     F->perm[j] = yes[j];
     293      186732 :   for (i=1; i<ino; i++, j++) F->perm[j] =  no[i];
     294      260302 :   for (   ; j<lv; j++)       F->perm[j] =  perm[j];
     295       66249 :   F->allsubFB = NULL;
     296       66249 :   F->idealperm = gclone(FB_aut_perm(F, auts, cyclic));
     297       66251 :   if (iyes) assign_subFB(F, yes, iyes);
     298       66251 :   set_avma(av);
     299       66251 : }
     300             : static int
     301       26419 : subFB_change(FB_t *F)
     302             : {
     303       26419 :   long i, iyes, minsFB = lg(F->subFB)-1, lv = F->KC + 1;
     304       26419 :   pari_sp av = avma;
     305       26419 :   GEN yes, L_jid = F->L_jid, present = zero_zv(lv-1);
     306             : 
     307       26419 :   if (F->sfb_chg == sfb_INCREASE) minsFB++;
     308             : 
     309       26419 :   yes = cgetg(minsFB+1, t_VECSMALL); iyes = 1;
     310       26419 :   if (L_jid)
     311             :   {
     312       33994 :     for (i = 1; i < lg(L_jid); i++)
     313             :     {
     314       33861 :       long l = L_jid[i];
     315       33861 :       if (bad_subFB(F, l)) continue;
     316       31636 :       yes[iyes++] = l;
     317       31636 :       present[l] = 1;
     318       31636 :       if (iyes > minsFB) break;
     319             :     }
     320             :   }
     321           0 :   else i = 1;
     322       26419 :   if (iyes <= minsFB)
     323             :   {
     324         294 :     for ( ; i < lv; i++)
     325             :     {
     326         221 :       long l = F->perm[i];
     327         221 :       if (present[l] || bad_subFB(F, l)) continue;
     328          67 :       yes[iyes++] = l;
     329          67 :       if (iyes > minsFB) break;
     330             :     }
     331         133 :     if (i == lv) return 0;
     332             :   }
     333       26346 :   if (zv_equal(F->subFB, yes))
     334             :   {
     335       25590 :     if (DEBUGLEVEL) err_printf("\n*** NOT Changing sub factor base\n");
     336             :   }
     337             :   else
     338             :   {
     339         756 :     if (DEBUGLEVEL) err_printf("\n*** Changing sub factor base\n");
     340         756 :     assign_subFB(F, yes, iyes);
     341             :   }
     342       26346 :   F->sfb_chg = 0; return gc_bool(av, 1);
     343             : }
     344             : 
     345             : /* make sure enough room to store n more relations */
     346             : static void
     347      122448 : pre_allocate(RELCACHE_t *cache, size_t n)
     348             : {
     349      122448 :   size_t len = (cache->last - cache->base) + n;
     350      122448 :   if (len >= cache->len) reallocate(cache, len << 1);
     351      122448 : }
     352             : 
     353             : void
     354      134434 : init_GRHcheck(GRHcheck_t *S, long N, long R1, double LOGD)
     355             : {
     356      134434 :   const double c1 = M_PI*M_PI/2;
     357      134434 :   const double c2 = 3.663862376709;
     358      134434 :   const double c3 = 3.801387092431; /* Euler + log(8*Pi)*/
     359      134434 :   S->clone = 0;
     360      134434 :   S->cN = R1*c2 + N*c1;
     361      134434 :   S->cD = LOGD - N*c3 - R1*M_PI/2;
     362      134434 :   S->maxprimes = 16000; /* sufficient for LIMC=176081*/
     363      134434 :   S->primes = (GRHprime_t*)pari_malloc(S->maxprimes*sizeof(*S->primes));
     364      134434 :   S->nprimes = 0;
     365      134434 :   S->limp = 0;
     366      134434 :   u_forprime_init(&S->P, 2, ULONG_MAX);
     367      134433 : }
     368             : 
     369             : void
     370      134434 : free_GRHcheck(GRHcheck_t *S)
     371             : {
     372      134434 :   if (S->clone)
     373             :   {
     374       64001 :     long i = S->nprimes;
     375             :     GRHprime_t *pr;
     376     7578954 :     for (pr = S->primes, i = S->nprimes; i > 0; pr++, i--) gunclone(pr->dec);
     377             :   }
     378      134436 :   pari_free(S->primes);
     379      134434 : }
     380             : 
     381             : int
     382     1530860 : GRHok(GRHcheck_t *S, double L, double SA, double SB)
     383             : {
     384     1530860 :   return (S->cD + (S->cN + 2*SB) / L - 2*SA < -1e-8);
     385             : }
     386             : 
     387             : /* Return factorization pattern of p: [f,n], where n[i] primes of
     388             :  * residue degree f[i] */
     389             : static GEN
     390     7511614 : get_fs(GEN nf, GEN P, GEN index, ulong p)
     391             : {
     392             :   long j, k, f, n, l;
     393             :   GEN fs, ns;
     394             : 
     395     7511614 :   if (umodiu(index, p))
     396             :   { /* easy case: p does not divide index */
     397     7472701 :     GEN F = Flx_degfact(ZX_to_Flx(P,p), p);
     398     7473552 :     fs = gel(F,1); l = lg(fs);
     399             :   }
     400             :   else
     401             :   {
     402       38507 :     GEN F = idealprimedec(nf, utoipos(p));
     403       38714 :     l = lg(F);
     404       38714 :     fs = cgetg(l, t_VECSMALL);
     405      121177 :     for (j = 1; j < l; j++) fs[j] = pr_get_f(gel(F,j));
     406             :   }
     407     7512266 :   ns = cgetg(l, t_VECSMALL);
     408     7509838 :   f = fs[1]; n = 1;
     409    13911797 :   for (j = 2, k = 1; j < l; j++)
     410     6401959 :     if (fs[j] == f)
     411     4677324 :       n++;
     412             :     else
     413             :     {
     414     1724635 :       ns[k] = n; fs[k] = f; k++;
     415     1724635 :       f = fs[j]; n = 1;
     416             :     }
     417     7509838 :   ns[k] = n; fs[k] = f; k++;
     418     7509838 :   setlg(fs, k);
     419     7508889 :   setlg(ns, k); return mkvec2(fs,ns);
     420             : }
     421             : 
     422             : /* cache data for all rational primes up to the LIM */
     423             : static void
     424      921200 : cache_prime_dec(GRHcheck_t *S, ulong LIM, GEN nf)
     425             : {
     426      921200 :   pari_sp av = avma;
     427             :   GRHprime_t *pr;
     428             :   GEN index, P;
     429             :   double nb;
     430             : 
     431      921200 :   if (S->limp >= LIM) return;
     432      329614 :   S->clone = 1;
     433      329614 :   nb = primepi_upper_bound((double)LIM); /* #{p <= LIM} <= nb */
     434      329620 :   GRH_ensure(S, nb+1); /* room for one extra prime */
     435      329621 :   P = nf_get_pol(nf);
     436      329620 :   index = nf_get_index(nf);
     437      329619 :   for (pr = S->primes + S->nprimes;;)
     438     7182384 :   {
     439     7512003 :     ulong p = u_forprime_next(&(S->P));
     440     7511671 :     pr->p = p;
     441     7511671 :     pr->logp = log((double)p);
     442     7511671 :     pr->dec = gclone(get_fs(nf, P, index, p));
     443     7512093 :     S->nprimes++;
     444     7512093 :     pr++;
     445     7512093 :     set_avma(av);
     446             :     /* store up to nextprime(LIM) included */
     447     7512007 :     if (p >= LIM) { S->limp = p; break; }
     448             :   }
     449             : }
     450             : 
     451             : static double
     452     2258439 : tailresback(long R1, long R2, double rK, long C, double C2, double C3, double r1K, double r2K, double logC, double logC2, double logC3)
     453             : {
     454     2258439 :   const double  rQ = 1.83787706641;
     455     2258439 :   const double r1Q = 1.98505372441;
     456     2258439 :   const double r2Q = 1.07991541347;
     457     4516878 :   return fabs((R1+R2-1)*(12*logC3+4*logC2-9*logC-6)/(2*C*logC3)
     458     2258439 :          + (rK-rQ)*(6*logC2 + 5*logC + 2)/(C*logC3)
     459     2258439 :          - R2*(6*logC2+11*logC+6)/(C2*logC2)
     460     2258439 :          - 2*(r1K-r1Q)*(3*logC2 + 4*logC + 2)/(C2*logC3)
     461     2258439 :          + (R1+R2-1)*(12*logC3+40*logC2+45*logC+18)/(6*C3*logC3)
     462     2258439 :          + (r2K-r2Q)*(2*logC2 + 3*logC + 2)/(C3*logC3));
     463             : }
     464             : 
     465             : static double
     466     1129233 : tailres(long R1, long R2, double al2K, double rKm, double rKM, double r1Km,
     467             :         double r1KM, double r2Km, double r2KM, double C, long i)
     468             : {
     469             :   /* C >= 3*2^i, lower bound for eint1(log(C)/2) */
     470             :   /* for(i=0,30,print(eint1(log(3*2^i)/2))) */
     471             :   static double tab[] = {
     472             :     0.50409264803,
     473             :     0.26205336997,
     474             :     0.14815491171,
     475             :     0.08770540561,
     476             :     0.05347651832,
     477             :     0.03328934284,
     478             :     0.02104510690,
     479             :     0.01346475900,
     480             :     0.00869778586,
     481             :     0.00566279855,
     482             :     0.00371111950,
     483             :     0.00244567837,
     484             :     0.00161948049,
     485             :     0.00107686891,
     486             :     0.00071868750,
     487             :     0.00048119961,
     488             :     0.00032312188,
     489             :     0.00021753772,
     490             :     0.00014679818,
     491             :     9.9272855581E-5,
     492             :     6.7263969995E-5,
     493             :     4.5656812967E-5,
     494             :     3.1041124593E-5,
     495             :     2.1136011590E-5,
     496             :     1.4411645381E-5,
     497             :     9.8393304088E-6,
     498             :     6.7257395409E-6,
     499             :     4.6025878272E-6,
     500             :     3.1529719271E-6,
     501             :     2.1620490021E-6,
     502             :     1.4839266071E-6
     503             :   };
     504     1129233 :   const double logC = log(C), logC2 = logC*logC, logC3 = logC*logC2;
     505     1129233 :   const double C2 = C*C, C3 = C*C2;
     506     1129233 :   double E1 = i >30? 0: tab[i];
     507     1129233 :   return al2K*((33*logC2+22*logC+8)/(8*logC3*sqrt(C))+15*E1/16)
     508     1129233 :     + maxdd(tailresback(rKm,r1KM,r2Km, C,C2,C3,R1,R2,logC,logC2,logC3),
     509     1129239 :             tailresback(rKM,r1Km,r2KM, C,C2,C3,R1,R2,logC,logC2,logC3))/2
     510     1129239 :     + ((R1+R2-1)*4*C+R2)*(C2+6*logC)/(4*C2*C2*logC2);
     511             : }
     512             : 
     513             : static long
     514       64000 : primeneeded(long N, long R1, long R2, double LOGD)
     515             : {
     516       64000 :   const double lim = 0.25; /* should be log(2)/2 == 0.34657... */
     517       64000 :   const double al2K =  0.3526*LOGD - 0.8212*N + 4.5007;
     518       64000 :   const double  rKm = -1.0155*LOGD + 2.1042*N - 8.3419;
     519       64000 :   const double  rKM = -0.5   *LOGD + 1.2076*N + 1;
     520       64000 :   const double r1Km = -       LOGD + 1.4150*N;
     521       64000 :   const double r1KM = -       LOGD + 1.9851*N;
     522       64000 :   const double r2Km = -       LOGD + 0.9151*N;
     523       64000 :   const double r2KM = -       LOGD + 1.0800*N;
     524       64000 :   long Cmin = 3, Cmax = 3, i = 0;
     525      574127 :   while (tailres(R1, R2, al2K, rKm, rKM, r1Km, r1KM, r2Km, r2KM, Cmax, i) > lim)
     526             :   {
     527      510127 :     Cmin = Cmax;
     528      510127 :     Cmax *= 2;
     529      510127 :     i++;
     530             :   }
     531       63994 :   i--;
     532      619195 :   while (Cmax - Cmin > 1)
     533             :   {
     534      555200 :     long t = (Cmin + Cmax)/2;
     535      555200 :     if (tailres(R1, R2, al2K, rKm, rKM, r1Km, r1KM, r2Km, r2KM, t, i) > lim)
     536      344300 :       Cmin = t;
     537             :     else
     538      210901 :       Cmax = t;
     539             :   }
     540       63995 :   return Cmax;
     541             : }
     542             : 
     543             : /* ~ 1 / Res(s = 1, zeta_K) */
     544             : static GEN
     545       64001 : compute_invres(GRHcheck_t *S, long LIMC)
     546             : {
     547       64001 :   pari_sp av = avma;
     548       64001 :   double loginvres = 0.;
     549             :   GRHprime_t *pr;
     550             :   long i;
     551       64001 :   double logLIMC = log((double)LIMC);
     552       64001 :   double logLIMC2 = logLIMC*logLIMC, denc;
     553             :   double c0, c1, c2;
     554       64001 :   denc = 1/(pow((double)LIMC, 3.) * logLIMC * logLIMC2);
     555       64001 :   c2 = (    logLIMC2 + 3 * logLIMC / 2 + 1) * denc;
     556       64001 :   denc *= LIMC;
     557       64001 :   c1 = (3 * logLIMC2 + 4 * logLIMC     + 2) * denc;
     558       64001 :   denc *= LIMC;
     559       64001 :   c0 = (3 * logLIMC2 + 5 * logLIMC / 2 + 1) * denc;
     560     7522275 :   for (pr = S->primes, i = S->nprimes; i > 0; pr++, i--)
     561             :   {
     562             :     GEN dec, fs, ns;
     563             :     long addpsi;
     564             :     double addpsi1, addpsi2;
     565     7514364 :     double logp = pr->logp, NPk;
     566     7514364 :     long j, k, limp = logLIMC/logp;
     567     7514364 :     ulong p = pr->p, p2 = p*p;
     568     7514364 :     if (limp < 1) break;
     569     7458274 :     dec = pr->dec;
     570     7458274 :     fs = gel(dec, 1); ns = gel(dec, 2);
     571     7458274 :     loginvres += 1./p;
     572             :     /* NB: limp = 1 nearly always and limp > 2 for very few primes */
     573     8824624 :     for (k=2, NPk = p; k <= limp; k++) { NPk *= p; loginvres += 1/(k * NPk); }
     574     7458274 :     addpsi = limp;
     575     7458274 :     addpsi1 = p *(pow((double)p , (double)limp)-1)/(p -1);
     576     7458274 :     addpsi2 = p2*(pow((double)p2, (double)limp)-1)/(p2-1);
     577     7458274 :     j = lg(fs);
     578    16630148 :     while (--j > 0)
     579             :     {
     580             :       long f, nb, kmax;
     581             :       double NP, NP2, addinvres;
     582     9171874 :       f = fs[j]; if (f > limp) continue;
     583     3983460 :       nb = ns[j];
     584     3983460 :       NP = pow((double)p, (double)f);
     585     3983460 :       addinvres = 1/NP;
     586     3983460 :       kmax = limp / f;
     587     4860310 :       for (k=2, NPk = NP; k <= kmax; k++) { NPk *= NP; addinvres += 1/(k*NPk); }
     588     3983460 :       NP2 = NP*NP;
     589     3983460 :       loginvres -= nb * addinvres;
     590     3983460 :       addpsi -= nb * f * kmax;
     591     3983460 :       addpsi1 -= nb*(f*NP *(pow(NP ,(double)kmax)-1)/(NP -1));
     592     3983460 :       addpsi2 -= nb*(f*NP2*(pow(NP2,(double)kmax)-1)/(NP2-1));
     593             :     }
     594     7458274 :     loginvres -= (addpsi*c0 - addpsi1*c1 + addpsi2*c2)*logp;
     595             :   }
     596       64001 :   return gc_leaf(av, mpexp(dbltor(loginvres)));
     597             : }
     598             : 
     599             : static long
     600       63999 : nthideal(GRHcheck_t *S, GEN nf, long n)
     601             : {
     602       63999 :   pari_sp av = avma;
     603       63999 :   GEN P = nf_get_pol(nf);
     604       63999 :   ulong p = 0, *vecN = (ulong*)const_vecsmall(n, LONG_MAX);
     605       63999 :   long i, N = poldegree(P, -1);
     606       63999 :   for (i = 0; ; i++)
     607      230578 :   {
     608             :     GRHprime_t *pr;
     609             :     GEN fs;
     610      294577 :     cache_prime_dec(S, p+1, nf);
     611      294578 :     pr = S->primes + i;
     612      294578 :     fs = gel(pr->dec, 1);
     613      294578 :     p = pr->p;
     614      294578 :     if (fs[1] != N)
     615             :     {
     616      198011 :       GEN ns = gel(pr->dec, 2);
     617      198011 :       long k, l, j = lg(fs);
     618      443720 :       while (--j > 0)
     619             :       {
     620      245709 :         ulong NP = upowuu(p, fs[j]);
     621             :         long nf;
     622      245709 :         if (!NP) continue;
     623      754375 :         for (k = 1; k <= n; k++) if (vecN[k] > NP) break;
     624      245317 :         if (k > n) continue;
     625             :         /* vecN[k] <= NP */
     626      158866 :         nf = ns[j]; /*#{primes of norme NP} = nf, insert them here*/
     627      355595 :         for (l = k+nf; l <= n; l++) vecN[l] = vecN[l-nf];
     628      401542 :         for (l = 0; l < nf && k+l <= n; l++) vecN[k+l] = NP;
     629      365199 :         while (l <= k) vecN[l++] = NP;
     630             :       }
     631             :     }
     632      294578 :     if (p > vecN[n]) break;
     633             :   }
     634       64000 :   return gc_long(av, vecN[n]);
     635             : }
     636             : 
     637             : /* volume of unit ball in R^n: \pi^{n/2} / \Gamma(n/2 + 1) */
     638             : static double
     639       66247 : ballvol(long n)
     640             : {
     641       66247 :   double v = odd(n)? 2: 1;
     642      151516 :   for (; n > 1; n -= 2) v *= (2 * M_PI) / n;
     643       66247 :   return v;
     644             : }
     645             : 
     646             : /* Compute FB, LV, iLP + KC*. Reset perm
     647             :  * C2: bound for norm of tested prime ideals (includes be_honest())
     648             :  * C1: bound for p, such that P|p (NP <= C2) used to build relations */
     649             : static void
     650       66250 : FBgen(FB_t *F, GEN nf, long N, ulong C1, ulong C2, GRHcheck_t *S)
     651             : {
     652             :   GRHprime_t *pr;
     653             :   long i, ip;
     654             :   GEN prim;
     655       66250 :   const double L = log((double)C2 + 0.5);
     656             : 
     657       66250 :   cache_prime_dec(S, C2, nf);
     658       66250 :   pr = S->primes;
     659       66250 :   F->sfb_chg = 0;
     660       66250 :   F->FB  = cgetg(C2+1, t_VECSMALL);
     661       66250 :   F->iLP = cgetg(C2+1, t_VECSMALL);
     662       66250 :   F->LV = zerovec(C2);
     663             : 
     664       66250 :   prim = icopy(gen_1);
     665       66252 :   i = ip = 0;
     666       66252 :   F->KC = F->KCZ = 0;
     667      438150 :   for (;; pr++) /* p <= C2 */
     668      438150 :   {
     669      504402 :     ulong p = pr->p;
     670             :     long k, l, m;
     671             :     GEN LP, nb, f;
     672             : 
     673      504402 :     if (!F->KC && p > C1) { F->KCZ = i; F->KC = ip; }
     674      504402 :     if (p > C2) break;
     675             : 
     676      467194 :     if (DEBUGLEVEL>1) err_printf(" %ld",p);
     677             : 
     678      467195 :     f = gel(pr->dec, 1); nb = gel(pr->dec, 2);
     679      467195 :     if (f[1] == N)
     680             :     {
     681      146468 :       if (p == C2) break;
     682      137928 :       continue; /* p inert */
     683             :     }
     684      320727 :     l = (long)(L/pr->logp); /* p^f <= C2  <=> f <= l */
     685      584608 :     for (k=0, m=1; m < lg(f) && f[m]<=l; m++) k += nb[m];
     686      320727 :     if (!k)
     687             :     { /* too inert to appear in FB */
     688       73555 :       if (p == C2) break;
     689       72701 :       continue;
     690             :     }
     691      247172 :     prim[2] = p; LP = idealprimedec_limit_f(nf,prim, l);
     692             :     /* keep noninert ideals with Norm <= C2 */
     693      247170 :     if (m == lg(f)) setisclone(LP); /* flag it: all prime divisors in FB */
     694      247170 :     F->FB[++i]= p;
     695      247170 :     gel(F->LV,p) = LP;
     696      247170 :     F->iLP[p] = ip; ip += k;
     697      247170 :     if (p == C2) break;
     698             :   }
     699       66251 :   if (!F->KC) { F->KCZ = i; F->KC = ip; }
     700             :   /* Note F->KC > 0 otherwise GRHchk is false */
     701       66251 :   setlg(F->FB, F->KCZ+1); F->KCZ2 = i;
     702       66250 :   F->prodZ = zv_prod_Z(F->FB);
     703       66248 :   if (DEBUGLEVEL>1)
     704             :   {
     705           0 :     err_printf("\n");
     706           0 :     if (DEBUGLEVEL>6)
     707             :     {
     708           0 :       err_printf("########## FACTORBASE ##########\n\n");
     709           0 :       err_printf("KC2=%ld, KC=%ld, KCZ=%ld, KCZ2=%ld\n",
     710             :                   ip, F->KC, F->KCZ, F->KCZ2);
     711           0 :       for (i=1; i<=F->KCZ; i++) err_printf("++ LV[%ld] = %Ps",i,gel(F->LV,F->FB[i]));
     712             :     }
     713             :   }
     714       66248 :   F->perm = NULL; F->L_jid = NULL;
     715       66248 :   F->ballvol = ballvol(nf_get_degree(nf));
     716       66247 : }
     717             : 
     718             : static int
     719      496385 : GRHchk(GEN nf, GRHcheck_t *S, ulong LIMC)
     720             : {
     721      496385 :   double logC = log((double)LIMC), SA = 0, SB = 0;
     722      496385 :   GRHprime_t *pr = S->primes;
     723             : 
     724      496385 :   cache_prime_dec(S, LIMC, nf);
     725      496384 :   for (pr = S->primes;; pr++)
     726     3084591 :   {
     727     3580975 :     ulong p = pr->p;
     728             :     GEN dec, fs, ns;
     729             :     double logCslogp;
     730             :     long j;
     731             : 
     732     3580975 :     if (p > LIMC) break;
     733     3190972 :     dec = pr->dec; fs = gel(dec, 1); ns = gel(dec,2);
     734     3190972 :     logCslogp = logC/pr->logp;
     735     5022085 :     for (j = 1; j < lg(fs); j++)
     736             :     {
     737     3929194 :       long f = fs[j], M, nb;
     738             :       double logNP, q, A, B;
     739     3929194 :       if (f > logCslogp) break;
     740     1831114 :       logNP = f * pr->logp;
     741     1831114 :       q = 1/sqrt((double)upowuu(p, f));
     742     1831113 :       A = logNP * q; B = logNP * A; M = (long)(logCslogp/f);
     743     1831113 :       if (M > 1)
     744             :       {
     745      376640 :         double inv1_q = 1 / (1-q);
     746      376640 :         A *= (1 - pow(q, (double)M)) * inv1_q;
     747      376640 :         B *= (1 - pow(q, (double)M)*(M+1 - M*q)) * inv1_q * inv1_q;
     748             :       }
     749     1831113 :       nb = ns[j];
     750     1831113 :       SA += nb * A;
     751     1831113 :       SB += nb * B;
     752             :     }
     753     3190971 :     if (p == LIMC) break;
     754             :   }
     755      496383 :   return GRHok(S, logC, SA, SB);
     756             : }
     757             : 
     758             : /*  SMOOTH IDEALS */
     759             : static void
     760     9461780 : store(long i, long e, FACT *fact)
     761             : {
     762     9461780 :   ++fact[0].pr;
     763     9461780 :   fact[fact[0].pr].pr = i; /* index */
     764     9461780 :   fact[fact[0].pr].ex = e; /* exponent */
     765     9461780 : }
     766             : 
     767             : /* divide out m by all P|p, k = v_p(Nm) */
     768             : static int
     769        2343 : divide_p_elt(GEN LP, long ip, long k, GEN m, FACT *fact)
     770             : {
     771        2343 :   long j, l = lg(LP);
     772        3188 :   for (j=1; j<l; j++)
     773             :   {
     774        3188 :     GEN P = gel(LP,j);
     775        3188 :     long v = ZC_nfval(m, P);
     776        3188 :     if (!v) continue;
     777        2771 :     store(ip + j, v, fact); /* v = v_P(m) > 0 */
     778        2771 :     k -= v * pr_get_f(P);
     779        2771 :     if (!k) return 1;
     780             :   }
     781           0 :   return 0;
     782             : }
     783             : /* divide out I by all P|p, k = v_p(NI) */
     784             : static int
     785      185478 : divide_p_id(GEN LP, long ip, long k, GEN nf, GEN I, FACT *fact)
     786             : {
     787      185478 :   long j, l = lg(LP);
     788      278162 :   for (j=1; j<l; j++)
     789             :   {
     790      270301 :     GEN P = gel(LP,j);
     791      270301 :     long v = idealval(nf,I, P);
     792      270300 :     if (!v) continue;
     793      181115 :     store(ip + j, v, fact); /* v = v_P(I) > 0 */
     794      181117 :     k -= v * pr_get_f(P);
     795      181117 :     if (!k) return 1;
     796             :   }
     797        7861 :   return 0;
     798             : }
     799             : /* divide out m/I by all P|p, k = v_p(Nm/NI) */
     800             : static int
     801     5436028 : divide_p_quo(GEN LP, long ip, long k, GEN nf, GEN I, GEN m, FACT *fact)
     802             : {
     803     5436028 :   long j, l = lg(LP);
     804    17749507 :   for (j=1; j<l; j++)
     805             :   {
     806    17660797 :     GEN P = gel(LP,j);
     807    17660797 :     long v = ZC_nfval(m, P);
     808    17659669 :     if (!v) continue;
     809     8106003 :     v -= idealval(nf,I, P);
     810     8107344 :     if (!v) continue;
     811     6887672 :     store(ip + j, v, fact); /* v = v_P(m / I) > 0 */
     812     6887707 :     k -= v * pr_get_f(P);
     813     6887630 :     if (!k) return 1;
     814             :   }
     815       88710 :   return 0;
     816             : }
     817             : 
     818             : static int
     819     5623840 : divide_p(FB_t *F, long p, long k, GEN nf, GEN I, GEN m, FACT *fact)
     820             : {
     821     5623840 :   GEN LP = gel(F->LV,p);
     822     5623840 :   long ip = F->iLP[p];
     823     5623840 :   if (!m) return divide_p_id (LP,ip,k,nf,I,fact);
     824     5438362 :   if (!I) return divide_p_elt(LP,ip,k,m,fact);
     825     5436019 :   return divide_p_quo(LP,ip,k,nf,I,m,fact);
     826             : }
     827             : 
     828             : /* Let x = m if I == NULL,
     829             :  *         I if m == NULL,
     830             :  *         m/I otherwise.
     831             :  * Can we factor the integral primitive ideal x ? |N| = Norm x > 0 */
     832             : static long
     833    18355117 : can_factor(FB_t *F, GEN nf, GEN I, GEN m, GEN N, FACT *fact)
     834             : {
     835             :   GEN f, p, e;
     836             :   long i, l;
     837    18355117 :   fact[0].pr = 0;
     838    18355117 :   if (is_pm1(N)) return 1;
     839    17376301 :   if (!is_pm1(Z_ppo(N, F->prodZ))) return 0;
     840     2841684 :   f = absZ_factor(N); p = gel(f,1); e = gel(f,2); l = lg(p);
     841     8369311 :   for (i = 1; i < l; i++)
     842     5623828 :     if (!divide_p(F, itou(gel(p,i)), itou(gel(e,i)), nf, I, m, fact))
     843             :     {
     844       96304 :       if (DEBUGLEVEL > 1) err_printf(".");
     845       96304 :       return 0;
     846             :     }
     847     2745483 :   return 1;
     848             : }
     849             : 
     850             : /* can we factor m/I ? [m in I from idealpseudomin_nonscalar], NI = norm I */
     851             : static long
     852    16942547 : factorgen(FB_t *F, GEN nf, GEN I, GEN NI, GEN m, FACT *fact)
     853             : {
     854             :   long e;
     855    16942547 :   GEN Nm = embed_norm(RgM_RgC_mul(nf_get_M(nf),m), nf_get_r1(nf));
     856    16942600 :   GEN N = grndtoi(NI? divri(Nm, NI): Nm, &e); /* ~ N(m/I) */
     857    16942531 :   if (e > -32)
     858             :   {
     859           0 :     if (DEBUGLEVEL > 1) err_printf("+");
     860           0 :     return 0;
     861             :   }
     862    16942531 :   return can_factor(F, nf, I, m, N, fact);
     863             : }
     864             : 
     865             : /*  FUNDAMENTAL UNITS */
     866             : 
     867             : /* a, y real. Return  (Re(x) + a) + I * (Im(x) % y) */
     868             : static GEN
     869     6906846 : addRe_modIm(GEN x, GEN a, GEN y, GEN iy)
     870             : {
     871             :   GEN z;
     872     6906846 :   if (typ(x) == t_COMPLEX)
     873             :   {
     874     4906342 :     GEN re, im = modRr_i(gel(x,2), y, iy);
     875     4906303 :     if (!im) return NULL;
     876     4906303 :     re = gadd(gel(x,1), a);
     877     4906280 :     z = gequal0(im)? re: mkcomplex(re, im);
     878             :   }
     879             :   else
     880     2000504 :     z = gadd(x, a);
     881     6906779 :   return z;
     882             : }
     883             : static GEN
     884      204620 : modIm(GEN x, GEN y, GEN iy)
     885             : {
     886      204620 :   if (typ(x) == t_COMPLEX)
     887             :   {
     888      191445 :     GEN im = modRr_i(gel(x,2), y, iy);
     889      191442 :     if (!im) return NULL;
     890      191442 :     x = gequal0(im)? gel(x,1): mkcomplex(gel(x,1), im);
     891             :   }
     892      204617 :   return x;
     893             : }
     894             : 
     895             : /* clean archimedean components. ipi = 2^n / pi (n arbitrary); its
     896             :  * exponent may be modified */
     897             : static GEN
     898     3071479 : cleanarch(GEN x, long N, GEN ipi, long prec)
     899             : {
     900             :   long i, l, R1, RU;
     901     3071479 :   GEN s, y = cgetg_copy(x, &l);
     902             : 
     903     3071476 :   if (!ipi) ipi = invr(mppi(prec));
     904     3071474 :   if (typ(x) == t_MAT)
     905             :   {
     906      529385 :     for (i = 1; i < l; i++)
     907      465235 :       if (!(gel(y,i) = cleanarch(gel(x,i), N, ipi, prec))) return NULL;
     908       64150 :     return y;
     909             :   }
     910     3007320 :   RU = l-1; R1 = (RU<<1) - N;
     911     3007320 :   s = gdivgs(RgV_sum(real_i(x)), -N); /* -log |norm(x)| / N */
     912     3007295 :   i = 1;
     913     3007295 :   if (R1)
     914             :   {
     915     2523880 :     GEN pi2 = Pi2n(1, prec);
     916     2523887 :     setexpo(ipi, -3); /* 1/(2pi) */
     917     7790474 :     for (; i <= R1; i++)
     918     5266616 :       if (!(gel(y,i) = addRe_modIm(gel(x,i), s, pi2, ipi))) return NULL;
     919             :   }
     920     3007273 :   if (i <= RU)
     921             :   {
     922     1080298 :     GEN pi4 = Pi2n(2, prec), s2 = gmul2n(s, 1);
     923     1080312 :     setexpo(ipi, -4); /* 1/(4pi) */
     924     2720580 :     for (; i <= RU; i++)
     925     1640238 :       if (!(gel(y,i) = addRe_modIm(gel(x,i), s2, pi4, ipi))) return NULL;
     926             :   }
     927     3007317 :   return y;
     928             : }
     929             : GEN
     930      197126 : nf_cxlog_normalize(GEN nf, GEN x, long prec)
     931             : {
     932      197126 :   long N = nf_get_degree(nf);
     933      197126 :   return cleanarch(x, N, NULL, prec);
     934             : }
     935             : 
     936             : /* clean unit archimedean components. ipi = 2^n / pi (n arbitrary); its
     937             :  * exponent may be modified */
     938             : static GEN
     939      133868 : cleanarchunit(GEN x, long N, GEN ipi, long prec)
     940             : {
     941             :   long i, l, R1, RU;
     942      133868 :   GEN y = cgetg_copy(x, &l);
     943             : 
     944      133868 :   if (!ipi) ipi = invr(mppi(prec));
     945      133868 :   if (typ(x) == t_MAT)
     946             :   {
     947      133861 :     for (i = 1; i < l; i++)
     948       69860 :       if (!(gel(y,i) = cleanarchunit(gel(x,i), N, ipi, prec))) return NULL;
     949       64001 :     return y;
     950             :   }
     951       69860 :   if (gexpo(RgV_sum(real_i(x))) > -10) return NULL;
     952       69852 :   RU = l-1; R1 = (RU<<1) - N;
     953       69852 :   i = 1;
     954       69852 :   if (R1)
     955             :   {
     956       55376 :     GEN pi2 = Pi2n(1, prec);
     957       55376 :     setexpo(ipi, -3); /* 1/(2pi) */
     958      189321 :     for (; i <= R1; i++)
     959      133949 :       if (!(gel(y,i) = modIm(gel(x,i), pi2, ipi))) return NULL;
     960             :   }
     961       69848 :   if (i <= RU)
     962             :   {
     963       34447 :     GEN pi4 = Pi2n(2, prec);
     964       34447 :     setexpo(ipi, -4); /* 1/(4pi) */
     965      105124 :     for (; i <= RU; i++)
     966       70672 :       if (!(gel(y,i) = modIm(gel(x,i), pi4, ipi))) return NULL;
     967             :   }
     968       69853 :   return y;
     969             : }
     970             : 
     971             : static GEN
     972         396 : not_given(long reason)
     973             : {
     974         396 :   if (DEBUGLEVEL)
     975           0 :     switch(reason)
     976             :     {
     977           0 :       case fupb_LARGE:
     978           0 :         pari_warn(warner,"fundamental units too large, not given");
     979           0 :         break;
     980           0 :       case fupb_PRECI:
     981           0 :         pari_warn(warner,"insufficient precision for fundamental units, not given");
     982           0 :         break;
     983             :     }
     984         396 :   return NULL;
     985             : }
     986             : 
     987             : /* check whether exp(x) will 1) get too big (real(x) large), 2) require
     988             :  * large accuracy for argument reduction (imag(x) large) */
     989             : static long
     990     2840326 : expbitprec(GEN x, long *e)
     991             : {
     992             :   GEN re, im;
     993     2840326 :   if (typ(x) != t_COMPLEX) re = x;
     994             :   else
     995             :   {
     996     1778704 :     im = gel(x,2); *e = maxss(*e, expo(im) + 5 - bit_prec(im));
     997     1778704 :     re = gel(x,1);
     998             :   }
     999     2840326 :   return (expo(re) <= 20);
    1000             : 
    1001             : }
    1002             : static long
    1003     1237088 : RgC_expbitprec(GEN x)
    1004             : {
    1005     1237088 :   long l = lg(x), i, e = - (long)HIGHEXPOBIT;
    1006     3872328 :   for (i = 1; i < l; i++)
    1007     2635814 :     if (!expbitprec(gel(x,i), &e)) return LONG_MAX;
    1008     1236514 :   return e;
    1009             : }
    1010             : static long
    1011       48790 : RgM_expbitprec(GEN x)
    1012             : {
    1013       48790 :   long i, j, I, J, e = - (long)HIGHEXPOBIT;
    1014       48790 :   RgM_dimensions(x, &I,&J);
    1015      118573 :   for (j = 1; j <= J; j++)
    1016      274295 :     for (i = 1; i <= I; i++)
    1017      204512 :       if (!expbitprec(gcoeff(x,i,j), &e)) return LONG_MAX;
    1018       48727 :   return e;
    1019             : }
    1020             : 
    1021             : static GEN
    1022        1379 : FlxqX_chinese_unit(GEN X, GEN U, GEN invzk, GEN D, GEN T, ulong p)
    1023             : {
    1024        1379 :   long i, lU = lg(U), lX = lg(X), d = lg(invzk)-1;
    1025        1379 :   GEN M = cgetg(lU, t_MAT);
    1026        1379 :   if (D)
    1027             :   {
    1028        1272 :     D = Flv_inv(D, p);
    1029       69740 :     for (i = 1; i < lX; i++)
    1030       68468 :       if (uel(D, i) != 1)
    1031       56623 :         gel(X,i) = Flx_Fl_mul(gel(X,i), uel(D,i), p);
    1032             :   }
    1033        3878 :   for (i = 1; i < lU; i++)
    1034             :   {
    1035        2499 :     GEN H = FlxqV_factorback(X, gel(U, i), T, p);
    1036        2499 :     gel(M, i) = Flm_Flc_mul(invzk, Flx_to_Flv(H, d), p);
    1037             :   }
    1038        1379 :   return M;
    1039             : }
    1040             : 
    1041             : static GEN
    1042         274 : chinese_unit_slice(GEN A, GEN U, GEN B, GEN D, GEN C, GEN P, GEN *mod)
    1043             : {
    1044         274 :   pari_sp av = avma;
    1045         274 :   long i, n = lg(P)-1, v = varn(C);
    1046             :   GEN H, T;
    1047         274 :   if (n == 1)
    1048             :   {
    1049           0 :     ulong p = uel(P,1);
    1050           0 :     GEN a = ZXV_to_FlxV(A, p), b = ZM_to_Flm(B, p), c = ZX_to_Flx(C, p);
    1051           0 :     GEN d = D ? ZV_to_Flv(D, p): NULL;
    1052           0 :     GEN Hp = FlxqX_chinese_unit(a, U, b, d, c, p);
    1053           0 :     H = gc_upto(av, Flm_to_ZM(Hp));
    1054           0 :     *mod = utoi(p);
    1055           0 :     return H;
    1056             :   }
    1057         274 :   T = ZV_producttree(P);
    1058         274 :   A = ZXC_nv_mod_tree(A, P, T, v);
    1059         274 :   B = ZM_nv_mod_tree(B, P, T);
    1060         274 :   D = D ? ZV_nv_mod_tree(D, P, T): NULL;
    1061         274 :   C = ZX_nv_mod_tree(C, P, T);
    1062             : 
    1063         274 :   H = cgetg(n+1, t_VEC);
    1064        1653 :   for(i=1; i <= n; i++)
    1065             :   {
    1066        1379 :     ulong p = P[i];
    1067        1379 :     GEN a = gel(A,i), b = gel(B,i), c = gel(C,i), d = D ? gel(D,i): NULL;
    1068        1379 :     gel(H,i) = FlxqX_chinese_unit(a, U, b, d, c, p);
    1069             :   }
    1070         274 :   H = nmV_chinese_center_tree_seq(H, P, T, ZV_chinesetree(P, T));
    1071         274 :   *mod = gmael(T, lg(T)-1, 1); return gc_all(av, 2, &H, mod);
    1072             : }
    1073             : 
    1074             : GEN
    1075         274 : chinese_unit_worker(GEN P, GEN A, GEN U, GEN B, GEN D, GEN C)
    1076             : {
    1077         274 :   GEN V = cgetg(3, t_VEC);
    1078         274 :   gel(V,1) = chinese_unit_slice(A, U, B, isintzero(D) ? NULL: D, C, P, &gel(V,2));
    1079         274 :   return V;
    1080             : }
    1081             : 
    1082             : /* Let x = \prod X[i]^E[i] = u, return u.
    1083             :  * If dX != NULL, X[i] = nX[i] / dX[i] where nX[i] is a ZX, dX[i] in Z */
    1084             : static GEN
    1085          94 : chinese_unit(GEN nf, GEN nX, GEN dX, GEN U, ulong bnd)
    1086             : {
    1087          94 :   pari_sp av = avma;
    1088          94 :   GEN f = nf_get_index(nf), T = nf_get_pol(nf), invzk = nf_get_invzk(nf);
    1089             :   GEN H, mod;
    1090             :   forprime_t S;
    1091          94 :   GEN worker = snm_closure(is_entry("_chinese_unit_worker"),
    1092             :                mkcol5(nX, U, invzk, dX? dX: gen_0, T));
    1093          94 :   init_modular_big(&S);
    1094          94 :   H = gen_crt("chinese_units", worker, &S, f, bnd, 0, &mod, nmV_chinese_center, FpM_center);
    1095          94 :   settyp(H, t_VEC); return gc_GEN(av, H);
    1096             : }
    1097             : 
    1098             : /* *pE a ZM */
    1099             : static void
    1100         164 : ZM_remove_unused(GEN *pE, GEN *pX)
    1101             : {
    1102         164 :   long j, k, l = lg(*pX);
    1103         164 :   GEN E = *pE, v = cgetg(l, t_VECSMALL);
    1104       16395 :   for (j = k = 1; j < l; j++)
    1105       16231 :     if (!ZMrow_equal0(E, j)) v[k++] = j;
    1106         164 :   if (k < l)
    1107             :   {
    1108         164 :     setlg(v, k);
    1109         164 :     *pX = vecpermute(*pX,v);
    1110         164 :     *pE = rowpermute(E,v);
    1111             :   }
    1112         164 : }
    1113             : 
    1114             : /* s = -log|norm(x)|/N */
    1115             : static GEN
    1116     1306928 : fixarch(GEN x, GEN s, long R1)
    1117             : {
    1118             :   long i, l;
    1119     1306928 :   GEN y = cgetg_copy(x, &l);
    1120     3644835 :   for (i = 1; i <= R1; i++) gel(y,i) = gadd(s, gel(x,i));
    1121     1810044 :   for (     ; i <   l; i++) gel(y,i) = gadd(s, gmul2n(gel(x,i),-1));
    1122     1306940 :   return y;
    1123             : }
    1124             : 
    1125             : static GEN
    1126       64001 : getfu(GEN nf, GEN *ptA, GEN *ptU, long prec)
    1127             : {
    1128       64001 :   GEN U, y, matep, A, T = nf_get_pol(nf), M = nf_get_M(nf);
    1129       64001 :   long e, j, R1, RU, N = degpol(T);
    1130             : 
    1131       64001 :   R1 = nf_get_r1(nf); RU = (N+R1) >> 1;
    1132       64001 :   if (RU == 1) return cgetg(1,t_VEC);
    1133             : 
    1134       48790 :   A = *ptA;
    1135       48790 :   matep = cgetg(RU,t_MAT);
    1136      118642 :   for (j = 1; j < RU; j++)
    1137             :   {
    1138       69853 :     GEN Aj = gel(A,j), s = gdivgs(RgV_sum(real_i(Aj)), -N);
    1139       69850 :     gel(matep,j) = fixarch(Aj, s, R1);
    1140             :   }
    1141       48789 :   U = lll(real_i(matep));
    1142       48790 :   if (lg(U) < RU) return not_given(fupb_PRECI);
    1143       48790 :   if (ptU) { *ptU = U; *ptA = A = RgM_ZM_mul(A,U); }
    1144       48790 :   y = RgM_ZM_mul(matep,U);
    1145       48790 :   e = RgM_expbitprec(y);
    1146       48790 :   if (e >= 0) return not_given(e == LONG_MAX? fupb_LARGE: fupb_PRECI);
    1147       48727 :   if (prec <= 0) prec = gprecision(A);
    1148       48727 :   y = RgM_solve_realimag(M, gexp(y,prec));
    1149       48727 :   if (!y) return not_given(fupb_PRECI);
    1150       48727 :   y = grndtoi(y, &e); if (e >= 0) return not_given(fupb_PRECI);
    1151       48400 :   settyp(y, t_VEC);
    1152             : 
    1153       48400 :   if (!ptU) *ptA = A = RgM_ZM_mul(A, U);
    1154      117505 :   for (j = 1; j < RU; j++)
    1155             :   { /* y[i] are hopefully unit generators. Normalize: smallest T2 norm */
    1156       69111 :     GEN u = gel(y,j), v = zk_inv(nf, u);
    1157       69113 :     if (!v || !is_pm1(Q_denom(v)) || ZV_isscalar(u))
    1158           8 :       return not_given(fupb_PRECI);
    1159       69105 :     if (gcmp(RgC_fpnorml2(v,DEFAULTPREC), RgC_fpnorml2(u,DEFAULTPREC)) < 0)
    1160             :     {
    1161       29885 :       gel(A,j) = RgC_neg(gel(A,j));
    1162       29885 :       if (ptU) gel(U,j) = ZC_neg(gel(U,j));
    1163       29885 :       u = v;
    1164             :     }
    1165       69105 :     gel(y,j) = nf_to_scalar_or_alg(nf, u);
    1166             :   }
    1167       48394 :   return y;
    1168             : }
    1169             : 
    1170             : static void
    1171           0 : err_units() { pari_err_PREC("makeunits [cannot get units, use bnfinit(,1)]"); }
    1172             : 
    1173             : /* bound for log2 |sigma(u)|, sigma complex embedding, u fundamental unit
    1174             :  * attached to bnf_get_logfu */
    1175             : static double
    1176          94 : log2fubound(GEN bnf)
    1177             : {
    1178          94 :   GEN LU = bnf_get_logfu(bnf);
    1179          94 :   long i, j, l = lg(LU), r1 = nf_get_r1(bnf_get_nf(bnf));
    1180          94 :   double e = 0.0;
    1181         330 :   for (j = 1; j < l; j++)
    1182             :   {
    1183         236 :     GEN u = gel(LU,j);
    1184         624 :     for (i = 1; i <= r1; i++)
    1185             :     {
    1186         388 :       GEN E = real_i(gel(u,i));
    1187         388 :       e = maxdd(e, gtodouble(E));
    1188             :     }
    1189         842 :     for (     ; i <= l; i++)
    1190             :     {
    1191         606 :       GEN E = real_i(gel(u,i));
    1192         606 :       e = maxdd(e, gtodouble(E) / 2);
    1193             :     }
    1194             :   }
    1195          94 :   return e / M_LN2;
    1196             : }
    1197             : /* bound for log2(|RgM_solve_realimag(M, y)|_oo / |y|_oo)*/
    1198             : static double
    1199          94 : log2Mbound(GEN nf)
    1200             : {
    1201          94 :   GEN G = nf_get_G(nf), D = nf_get_disc(nf);
    1202          94 :   long r2 = nf_get_r2(nf), l = lg(G), i;
    1203          94 :   double e, d = dbllog2(D)/2 - r2 * M_LN2; /* log2 |det(split_realimag(M))| */
    1204          94 :   e = log2(nf_get_degree(nf));
    1205         535 :   for (i = 2; i < l; i++) e += dbllog2(gnorml2(gel(G,i))); /* Hadamard bound */
    1206          94 :   return e / 2 - d;
    1207             : }
    1208             : 
    1209             : static GEN
    1210          94 : vec_chinese_units(GEN bnf)
    1211             : {
    1212          94 :   GEN nf = bnf_get_nf(bnf), SUnits = bnf_get_sunits(bnf);
    1213          94 :   double bnd = ceil(log2Mbound(nf) + log2fubound(bnf));
    1214          94 :   GEN X, dX, Y, U, f = nf_get_index(nf);
    1215          94 :   long j, l, v = nf_get_varn(nf);
    1216          94 :   if (!SUnits) err_units(); /* no compact units */
    1217          94 :   Y = gel(SUnits,1);
    1218          94 :   U = gel(SUnits,2);
    1219          94 :   ZM_remove_unused(&U, &Y); l = lg(Y); X = cgetg(l, t_VEC);
    1220          94 :   if (is_pm1(f)) f = dX = NULL; else dX = cgetg(l, t_VEC);
    1221        5142 :   for (j = 1; j < l; j++)
    1222             :   {
    1223        5048 :     GEN t = nf_to_scalar_or_alg(nf, gel(Y,j));
    1224        5048 :     if (f)
    1225             :     {
    1226             :       GEN den;
    1227        4202 :       t = Q_remove_denom(t, &den);
    1228        4202 :       gel(dX,j) = den ? den: gen_1;
    1229             :     }
    1230        5048 :     gel(X,j) = typ(t) == t_INT? scalarpol_shallow(t,v): t;
    1231             :   }
    1232          94 :   if (dblexpo(bnd) >= BITS_IN_LONG)
    1233           0 :     pari_err_OVERFLOW("vec_chinese_units [units too large]");
    1234          94 :   return chinese_unit(nf, X, dX, U, (ulong)bnd);
    1235             : }
    1236             : 
    1237             : static GEN
    1238       24914 : makeunits(GEN bnf)
    1239             : {
    1240       24914 :   GEN nf = bnf_get_nf(bnf), fu = bnf_get_fu_nocheck(bnf);
    1241       24914 :   GEN tu = nf_to_scalar_or_basis(nf, bnf_get_tuU(bnf));
    1242       24914 :   fu = (typ(fu) == t_MAT)? vec_chinese_units(bnf): matalgtobasis(nf, fu);
    1243       24915 :   return vec_prepend(fu, tu);
    1244             : }
    1245             : 
    1246             : /*******************************************************************/
    1247             : /*                                                                 */
    1248             : /*           PRINCIPAL IDEAL ALGORITHM (DISCRETE LOG)              */
    1249             : /*                                                                 */
    1250             : /*******************************************************************/
    1251             : 
    1252             : /* G: prime ideals, E: vector of nonnegative exponents.
    1253             :  * C = possible extra prime (^1) or NULL
    1254             :  * Return Norm (product) */
    1255             : static GEN
    1256          69 : get_norm_fact_primes(GEN G, GEN E, GEN C)
    1257             : {
    1258          69 :   pari_sp av=avma;
    1259          69 :   GEN N = gen_1, P, p;
    1260          69 :   long i, c = lg(E);
    1261          69 :   for (i=1; i<c; i++)
    1262             :   {
    1263           0 :     GEN ex = gel(E,i);
    1264           0 :     long s = signe(ex);
    1265           0 :     if (!s) continue;
    1266             : 
    1267           0 :     P = gel(G,i); p = pr_get_p(P);
    1268           0 :     N = mulii(N, powii(p, mului(pr_get_f(P), ex)));
    1269             :   }
    1270          69 :   if (C) N = mulii(N, pr_norm(C));
    1271          69 :   return gc_INT(av, N);
    1272             : }
    1273             : 
    1274             : /* gen: HNF ideals */
    1275             : static GEN
    1276     1231475 : get_norm_fact(GEN gen, GEN ex, GEN *pd)
    1277             : {
    1278     1231475 :   long i, c = lg(ex);
    1279             :   GEN d,N,I,e,n,ne,de;
    1280     1231475 :   d = N = gen_1;
    1281     1528233 :   for (i=1; i<c; i++)
    1282      296758 :     if (signe(gel(ex,i)))
    1283             :     {
    1284      175574 :       I = gel(gen,i); e = gel(ex,i); n = ZM_det_triangular(I);
    1285      175574 :       ne = powii(n,e);
    1286      175574 :       de = equalii(n, gcoeff(I,1,1))? ne: powii(gcoeff(I,1,1), e);
    1287      175574 :       N = mulii(N, ne);
    1288      175574 :       d = mulii(d, de);
    1289             :     }
    1290     1231475 :   *pd = d; return N;
    1291             : }
    1292             : 
    1293             : static GEN
    1294     1392614 : get_pr_lists(GEN FB, long N, int list_pr)
    1295             : {
    1296             :   GEN pr, L;
    1297     1392614 :   long i, l = lg(FB), p, pmax;
    1298             : 
    1299     1392614 :   pmax = 0;
    1300     9558023 :   for (i=1; i<l; i++)
    1301             :   {
    1302     8165409 :     pr = gel(FB,i); p = pr_get_smallp(pr);
    1303     8165409 :     if (p > pmax) pmax = p;
    1304             :   }
    1305     1392614 :   L = const_vec(pmax, NULL);
    1306     1392614 :   if (list_pr)
    1307             :   {
    1308           0 :     for (i=1; i<l; i++)
    1309             :     {
    1310           0 :       pr = gel(FB,i); p = pr_get_smallp(pr);
    1311           0 :       if (!L[p]) gel(L,p) = vectrunc_init(N+1);
    1312           0 :       vectrunc_append(gel(L,p), pr);
    1313             :     }
    1314           0 :     for (p=1; p<=pmax; p++)
    1315           0 :       if (L[p]) gen_sort_inplace(gel(L,p), (void*)&cmp_prime_over_p,
    1316             :                                  &cmp_nodata, NULL);
    1317             :   }
    1318             :   else
    1319             :   {
    1320     9558020 :     for (i=1; i<l; i++)
    1321             :     {
    1322     8165407 :       pr = gel(FB,i); p = pr_get_smallp(pr);
    1323     8165407 :       if (!L[p]) gel(L,p) = vecsmalltrunc_init(N+1);
    1324     8165406 :       vecsmalltrunc_append(gel(L,p), i);
    1325             :     }
    1326             :   }
    1327     1392613 :   return L;
    1328             : }
    1329             : 
    1330             : /* recover FB, LV, iLP, KCZ from Vbase */
    1331             : static GEN
    1332     1392614 : recover_partFB(FB_t *F, GEN Vbase, long N)
    1333             : {
    1334     1392614 :   GEN FB, LV, iLP, L = get_pr_lists(Vbase, N, 0);
    1335     1392613 :   long l = lg(L), p, ip, i;
    1336             : 
    1337     1392613 :   i = ip = 0;
    1338     1392613 :   FB = cgetg(l, t_VECSMALL);
    1339     1392614 :   iLP= cgetg(l, t_VECSMALL);
    1340     1392612 :   LV = cgetg(l, t_VEC);
    1341    20446863 :   for (p = 2; p < l; p++)
    1342             :   {
    1343    19054249 :     if (!L[p]) continue;
    1344     4455878 :     FB[++i] = p;
    1345     4455878 :     gel(LV,p) = vecpermute(Vbase, gel(L,p));
    1346     4455879 :     iLP[p]= ip; ip += lg(gel(L,p))-1;
    1347             :   }
    1348     1392614 :   F->KCZ = i;
    1349     1392614 :   F->KC = ip;
    1350     1392614 :   F->FB = FB; setlg(FB, i+1);
    1351     1392612 :   F->prodZ = zv_prod_Z(F->FB);
    1352     1392612 :   F->LV = LV;
    1353     1392612 :   F->iLP= iLP; return L;
    1354             : }
    1355             : 
    1356             : /* add v^e to factorization */
    1357             : static void
    1358     2919764 : add_to_fact(long v, long e, FACT *fact)
    1359             : {
    1360     2919764 :   long i, n = fact[0].pr;
    1361     9910470 :   for (i=1; i<=n; i++)
    1362     7520247 :     if (fact[i].pr == v) { fact[i].ex += e; return; }
    1363     2390223 :   store(v, e, fact);
    1364             : }
    1365             : static void
    1366           0 : inv_fact(FACT *fact)
    1367             : {
    1368           0 :   long i, n = fact[0].pr;
    1369           0 :   for (i=1; i<=n; i++) fact[i].ex = -fact[i].ex;
    1370           0 : }
    1371             : 
    1372             : /* L (small) list of primes above the same p including pr. Return pr index */
    1373             : static int
    1374        3461 : pr_index(GEN L, GEN pr)
    1375             : {
    1376        3461 :   long j, l = lg(L);
    1377        3461 :   GEN al = pr_get_gen(pr);
    1378        3461 :   for (j=1; j<l; j++)
    1379        3461 :     if (ZV_equal(al, pr_get_gen(gel(L,j)))) return j;
    1380           0 :   pari_err_BUG("codeprime");
    1381             :   return 0; /* LCOV_EXCL_LINE */
    1382             : }
    1383             : 
    1384             : static long
    1385        3461 : Vbase_to_FB(FB_t *F, GEN pr)
    1386             : {
    1387        3461 :   long p = pr_get_smallp(pr);
    1388        3461 :   return F->iLP[p] + pr_index(gel(F->LV,p), pr);
    1389             : }
    1390             : 
    1391             : /* x, y 2 extended ideals whose first component is an integral HNF and second
    1392             :  * a famat */
    1393             : static GEN
    1394        3537 : idealHNF_mulred(GEN nf, GEN x, GEN y)
    1395             : {
    1396        3537 :   GEN A = idealHNF_mul(nf, gel(x,1), gel(y,1));
    1397        3537 :   GEN F = famat_mul_shallow(gel(x,2), gel(y,2));
    1398        3537 :   return idealred(nf, mkvec2(A, F));
    1399             : }
    1400             : /* idealred(x * pr^n), n > 0 is small, x extended ideal. Reduction in order to
    1401             :  * avoid prec pb: don't let id become too large as lgsub increases */
    1402             : static GEN
    1403        4663 : idealmulpowprime2(GEN nf, GEN x, GEN pr, ulong n)
    1404             : {
    1405        4663 :   GEN A = idealmulpowprime(nf, gel(x,1), pr, utoipos(n));
    1406        4663 :   return mkvec2(A, gel(x,2));
    1407             : }
    1408             : static GEN
    1409       65805 : init_famat(GEN x) { return mkvec2(x, trivial_fact()); }
    1410             : /* optimized idealfactorback + reduction; z = init_famat() */
    1411             : static GEN
    1412       28784 : genback(GEN z, GEN nf, GEN P, GEN E)
    1413             : {
    1414       28784 :   long i, l = lg(E);
    1415       28784 :   GEN I = NULL;
    1416       76689 :   for (i = 1; i < l; i++)
    1417       47905 :     if (signe(gel(E,i)))
    1418             :     {
    1419             :       GEN J;
    1420       32321 :       gel(z,1) = gel(P,i);
    1421       32321 :       J = idealpowred(nf, z, gel(E,i));
    1422       32321 :       I = I? idealHNF_mulred(nf, I, J): J;
    1423             :     }
    1424       28784 :   return I; /* != NULL since a generator */
    1425             : }
    1426             : 
    1427             : static GEN
    1428     1252848 : SPLIT_i(FB_t *F, GEN nf, GEN G, GEN x, GEN xred, GEN Nx, FACT *fact)
    1429             : {
    1430     1252848 :   pari_sp av = avma;
    1431     1252848 :   GEN L = idealpseudominvec(xred, G);
    1432     1252849 :   long k, l = lg(L);
    1433     1336537 :   for(k = 1; k < l; k++)
    1434     1320449 :     if (factorgen(F, nf, x, Nx, gel(L,k), fact)) return gel(L,k);
    1435       16088 :   return gc_NULL(av);
    1436             : }
    1437             : /* return famat y (principal ideal) such that y / x is smooth [wrt Vbase] */
    1438             : static GEN
    1439     1408956 : SPLIT(FB_t *F, GEN nf, GEN x, GEN Vbase, FACT *fact)
    1440             : {
    1441     1408956 :   GEN vecG, ex, y, x0, Nx = ZM_det_triangular(x);
    1442             :   long nbtest_lim, nbtest, i, j, ru, lgsub;
    1443             :   pari_sp av;
    1444             : 
    1445             :   /* try without reduction if x is small */
    1446     2817704 :   if (expi(gcoeff(x,1,1)) < 100 &&
    1447     1580945 :       can_factor(F, nf, x, NULL, Nx, fact)) return NULL;
    1448     1236759 :   if ((y = SPLIT_i(F, nf, nf_get_roundG(nf), x, x, Nx, fact))) return y;
    1449             : 
    1450             :   /* reduce in various directions */
    1451        8866 :   ru = lg(nf_get_roots(nf));
    1452        8866 :   vecG = cgetg(ru, t_VEC);
    1453       14471 :   for (j=1; j<ru; j++)
    1454             :   {
    1455       12667 :     gel(vecG,j) = nf_get_Gtwist1(nf, j);
    1456       12667 :     if ((y = SPLIT_i(F, nf, gel(vecG,j), x, x, Nx, fact))) return y;
    1457             :   }
    1458             : 
    1459             :   /* tough case, multiply by random products */
    1460        1804 :   lgsub = 3; nbtest = 1; nbtest_lim = 4;
    1461        1804 :   ex = cgetg(lgsub, t_VECSMALL);
    1462        1804 :   x0 = init_famat(x);
    1463             :   for(;;)
    1464         629 :   {
    1465        2433 :     GEN Ired, I, NI, id = x0;
    1466        2433 :     av = avma;
    1467        2433 :     if (DEBUGLEVEL>2) err_printf("# ideals tried = %ld\n",nbtest);
    1468        7411 :     for (i=1; i<lgsub; i++)
    1469             :     {
    1470        4978 :       ex[i] = random_bits(RANDOM_BITS);
    1471        4978 :       if (ex[i]) id = idealmulpowprime2(nf, id, gel(Vbase,i), ex[i]);
    1472             :     }
    1473        2433 :     if (id == x0) continue;
    1474             :     /* I^(-1) * \prod Vbase[i]^ex[i] = (id[2]) / x */
    1475             : 
    1476        2412 :     I = gel(id,1); NI = ZM_det_triangular(I);
    1477        2412 :     if (can_factor(F, nf, I, NULL, NI, fact))
    1478             :     {
    1479           0 :       inv_fact(fact); /* I^(-1) */
    1480           0 :       for (i=1; i<lgsub; i++)
    1481           0 :         if (ex[i]) add_to_fact(Vbase_to_FB(F,gel(Vbase,i)), ex[i], fact);
    1482           0 :       return gel(id,2);
    1483             :     }
    1484        2412 :     Ired = ru == 2? I: ZM_lll(I, 0.99, LLL_INPLACE);
    1485        4029 :     for (j=1; j<ru; j++)
    1486        3421 :       if ((y = SPLIT_i(F, nf, gel(vecG,j), I, Ired, NI, fact)))
    1487             :       {
    1488        5433 :         for (i=1; i<lgsub; i++)
    1489        3629 :           if (ex[i]) add_to_fact(Vbase_to_FB(F,gel(Vbase,i)), ex[i], fact);
    1490        1804 :         return famat_mul_shallow(gel(id,2), y);
    1491             :       }
    1492         608 :     set_avma(av);
    1493         608 :     if (++nbtest > nbtest_lim)
    1494             :     {
    1495          21 :       nbtest = 0;
    1496          21 :       if (++lgsub < minss(8, lg(Vbase)-1))
    1497             :       {
    1498          21 :         nbtest_lim <<= 1;
    1499          21 :         ex = cgetg(lgsub, t_VECSMALL);
    1500             :       }
    1501           0 :       else nbtest_lim = LONG_MAX; /* don't increase further */
    1502          21 :       if (DEBUGLEVEL>2) err_printf("SPLIT: increasing factor base [%ld]\n",lgsub);
    1503             :     }
    1504             :   }
    1505             : }
    1506             : 
    1507             : INLINE GEN
    1508     1397525 : bnf_get_W(GEN bnf) { return gel(bnf,1); }
    1509             : INLINE GEN
    1510     2785115 : bnf_get_B(GEN bnf) { return gel(bnf,2); }
    1511             : INLINE GEN
    1512     2819258 : bnf_get_C(GEN bnf) { return gel(bnf,4); }
    1513             : INLINE GEN
    1514     1392632 : bnf_get_vbase(GEN bnf) { return gel(bnf,5); }
    1515             : INLINE GEN
    1516     1392549 : bnf_get_Ur(GEN bnf) { return gmael(bnf,9,1); }
    1517             : INLINE GEN
    1518      271827 : bnf_get_ga(GEN bnf) { return gmael(bnf,9,2); }
    1519             : INLINE GEN
    1520      276783 : bnf_get_GD(GEN bnf) { return gmael(bnf,9,3); }
    1521             : 
    1522             : /* Return y (as an elt of K or a t_MAT representing an elt in Z[K])
    1523             :  * such that x / (y) is smooth and store the exponents of  its factorization
    1524             :  * on g_W and g_B in Wex / Bex; return NULL for y = 1 */
    1525             : static GEN
    1526     1392549 : split_ideal(GEN bnf, GEN x, GEN *pWex, GEN *pBex)
    1527             : {
    1528     1392549 :   GEN L, y, Vbase = bnf_get_vbase(bnf);
    1529     1392549 :   GEN Wex, W  = bnf_get_W(bnf);
    1530     1392549 :   GEN Bex, B  = bnf_get_B(bnf);
    1531             :   long p, j, i, l, nW, nB;
    1532             :   FACT *fact;
    1533             :   FB_t F;
    1534             : 
    1535     1392549 :   L = recover_partFB(&F, Vbase, lg(x)-1);
    1536     1392549 :   fact = (FACT*)stack_malloc((F.KC+1)*sizeof(FACT));
    1537     1392547 :   y = SPLIT(&F, bnf_get_nf(bnf), x, Vbase, fact);
    1538     1392549 :   nW = lg(W)-1; *pWex = Wex = zero_zv(nW);
    1539     1392549 :   nB = lg(B)-1; *pBex = Bex = zero_zv(nB); l = lg(F.FB);
    1540     1392549 :   p = j = 0; /* -Wall */
    1541     2092934 :   for (i = 1; i <= fact[0].pr; i++)
    1542             :   { /* decode index C = ip+j --> (p,j) */
    1543      700385 :     long a, b, t, C = fact[i].pr;
    1544     1953386 :     for (t = 1; t < l; t++)
    1545             :     {
    1546     1865910 :       long q = F.FB[t], k = C - F.iLP[q];
    1547     1865910 :       if (k <= 0) break;
    1548     1253001 :       p = q;
    1549     1253001 :       j = k;
    1550             :     }
    1551      700385 :     a = gel(L, p)[j];
    1552      700385 :     b = a - nW;
    1553      700385 :     if (b <= 0) Wex[a] = y? -fact[i].ex: fact[i].ex;
    1554      546764 :     else        Bex[b] = y? -fact[i].ex: fact[i].ex;
    1555             :   }
    1556     1392549 :   return y;
    1557             : }
    1558             : 
    1559             : GEN
    1560     1107813 : init_red_mod_units(GEN bnf, long prec)
    1561             : {
    1562     1107813 :   GEN s = gen_0, p1,s1,mat, logfu = bnf_get_logfu(bnf);
    1563     1107813 :   long i,j, RU = lg(logfu);
    1564             : 
    1565     1107813 :   if (RU == 1) return NULL;
    1566     1107813 :   mat = cgetg(RU,t_MAT);
    1567     2507125 :   for (j=1; j<RU; j++)
    1568             :   {
    1569     1399314 :     p1 = cgetg(RU+1,t_COL); gel(mat,j) = p1;
    1570     1399314 :     s1 = gen_0;
    1571     3465874 :     for (i=1; i<RU; i++)
    1572             :     {
    1573     2066562 :       gel(p1,i) = real_i(gcoeff(logfu,i,j));
    1574     2066562 :       s1 = mpadd(s1, mpsqr(gel(p1,i)));
    1575             :     }
    1576     1399312 :     gel(p1,RU) = gen_0; if (mpcmp(s1,s) > 0) s = s1;
    1577             :   }
    1578     1107811 :   s = gsqrt(gmul2n(s,RU),prec);
    1579     1107813 :   if (expo(s) < 27) s = utoipos(1UL << 27);
    1580     1107811 :   return mkvec2(mat, s);
    1581             : }
    1582             : 
    1583             : /* z computed above. Return unit exponents that would reduce col (arch) */
    1584             : GEN
    1585     1107810 : red_mod_units(GEN col, GEN z)
    1586             : {
    1587             :   long i,RU;
    1588             :   GEN x,mat,N2;
    1589             : 
    1590     1107810 :   if (!z) return NULL;
    1591     1107810 :   mat= gel(z,1);
    1592     1107810 :   N2 = gel(z,2);
    1593     1107810 :   RU = lg(mat); x = cgetg(RU+1,t_COL);
    1594     2507123 :   for (i=1; i<RU; i++) gel(x,i) = real_i(gel(col,i));
    1595     1107811 :   gel(x,RU) = N2;
    1596     1107811 :   x = lll(shallowconcat(mat,x));
    1597     1107813 :   if (typ(x) != t_MAT || lg(x) <= RU) return NULL;
    1598     1107813 :   x = gel(x,RU);
    1599     1107813 :   if (signe(gel(x,RU)) < 0) x = gneg_i(x);
    1600     1107813 :   if (!gequal1(gel(x,RU))) pari_err_BUG("red_mod_units");
    1601     1107813 :   setlg(x,RU); return x;
    1602             : }
    1603             : 
    1604             : static GEN
    1605     2250484 : add(GEN a, GEN t) { return a = a? RgC_add(a,t): t; }
    1606             : 
    1607             : /* [x] archimedian components, A column vector. return [x] A */
    1608             : static GEN
    1609     2057279 : act_arch(GEN A, GEN x)
    1610             : {
    1611             :   GEN a;
    1612     2057279 :   long i,l = lg(A), tA = typ(A);
    1613     2057279 :   if (tA == t_MAT)
    1614             :   { /* assume lg(x) >= l */
    1615      192290 :     a = cgetg(l, t_MAT);
    1616      282152 :     for (i=1; i<l; i++) gel(a,i) = act_arch(gel(A,i), x);
    1617      192291 :     return a;
    1618             :   }
    1619     1864989 :   if (l==1) return cgetg(1, t_COL);
    1620     1864989 :   a = NULL;
    1621     1864989 :   if (tA == t_VECSMALL)
    1622             :   {
    1623     7202978 :     for (i=1; i<l; i++)
    1624             :     {
    1625     5971506 :       long c = A[i];
    1626     5971506 :       if (c) a = add(a, gmulsg(c, gel(x,i)));
    1627             :     }
    1628             :   }
    1629             :   else
    1630             :   { /* A a t_COL of t_INT. Assume lg(A)==lg(x) */
    1631     1384260 :     for (i=1; i<l; i++)
    1632             :     {
    1633      750746 :       GEN c = gel(A,i);
    1634      750746 :       if (signe(c)) a = add(a, gmul(c, gel(x,i)));
    1635             :     }
    1636             :   }
    1637     1864986 :   return a? a: zerocol(lgcols(x)-1);
    1638             : }
    1639             : /* act_arch(matdiagonal(v), x) */
    1640             : static GEN
    1641       64096 : diagact_arch(GEN v, GEN x)
    1642             : {
    1643       64096 :   long i, l = lg(v);
    1644       64096 :   GEN a = cgetg(l, t_MAT);
    1645       92951 :   for (i = 1; i < l; i++) gel(a,i) = gmul(gel(x,i), gel(v,i));
    1646       64097 :   return a;
    1647             : }
    1648             : 
    1649             : static long
    1650     1410518 : prec_arch(GEN bnf)
    1651             : {
    1652     1410518 :   GEN a = bnf_get_C(bnf);
    1653     1410518 :   long i, l = lg(a), prec;
    1654             : 
    1655     1410518 :   for (i=1; i<l; i++)
    1656     1410434 :     if ( (prec = gprecision(gel(a,i))) ) return prec;
    1657          84 :   return DEFAULTPREC;
    1658             : }
    1659             : 
    1660             : static long
    1661        3857 : needed_bitprec(GEN x)
    1662             : {
    1663        3857 :   long i, e = 0, l = lg(x);
    1664       22552 :   for (i = 1; i < l; i++)
    1665             :   {
    1666       18695 :     GEN c = gel(x,i);
    1667       18695 :     long f = gexpo(c) - gprecision(c);
    1668       18695 :     if (f > e) e = f;
    1669             :   }
    1670        3857 :   return e;
    1671             : }
    1672             : 
    1673             : /* col = archimedian components of x, Nx its norm, dx a multiple of its
    1674             :  * denominator. Return x or NULL (fail) */
    1675             : GEN
    1676     1237084 : isprincipalarch(GEN bnf, GEN col, GEN kNx, GEN e, GEN dx, long *pe)
    1677             : {
    1678             :   GEN nf, x, y, logfu, s, M;
    1679     1237084 :   long N, prec = gprecision(col);
    1680     1237086 :   bnf = checkbnf(bnf); nf = bnf_get_nf(bnf); M = nf_get_M(nf);
    1681     1237086 :   if (!prec) prec = prec_arch(bnf);
    1682     1237086 :   *pe = 128;
    1683     1237086 :   logfu = bnf_get_logfu(bnf);
    1684     1237086 :   N = nf_get_degree(nf);
    1685     1237086 :   if (!(col = cleanarch(col,N,NULL,prec))) return NULL;
    1686     1237087 :   if (lg(col) > 2)
    1687             :   { /* reduce mod units */
    1688     1107813 :     GEN u, z = init_red_mod_units(bnf,prec);
    1689     1107810 :     if (!(u = red_mod_units(col,z))) return NULL;
    1690     1107813 :     col = RgC_add(col, RgM_RgC_mul(logfu, u));
    1691     1107813 :     if (!(col = cleanarch(col,N,NULL,prec))) return NULL;
    1692             :   }
    1693     1237085 :   s = divru(mulir(e, glog(kNx,prec)), N);
    1694     1237079 :   col = fixarch(col, s, nf_get_r1(nf));
    1695     1237088 :   if (RgC_expbitprec(col) >= 0) return NULL;
    1696     1236514 :   col = gexp(col, prec);
    1697             :   /* d.alpha such that x = alpha \prod gj^ej */
    1698     1236514 :   x = RgM_solve_realimag(M,col); if (!x) return NULL;
    1699     1236511 :   x = RgC_Rg_mul(x, dx);
    1700     1236510 :   y = grndtoi(x, pe);
    1701     1236512 :   if (*pe > -5) { *pe = needed_bitprec(x); return NULL; }
    1702     1232655 :   return RgC_Rg_div(y, dx);
    1703             : }
    1704             : 
    1705             : /* y = C \prod g[i]^e[i] ? */
    1706             : static int
    1707     1228546 : fact_ok(GEN nf, GEN y, GEN C, GEN g, GEN e)
    1708             : {
    1709     1228546 :   pari_sp av = avma;
    1710     1228546 :   long i, c = lg(e);
    1711     1228546 :   GEN z = C? C: gen_1;
    1712     1505577 :   for (i=1; i<c; i++)
    1713      277031 :     if (signe(gel(e,i))) z = idealmul(nf, z, idealpow(nf, gel(g,i), gel(e,i)));
    1714     1228546 :   if (typ(z) != t_MAT) z = idealhnf_shallow(nf,z);
    1715     1228546 :   if (typ(y) != t_MAT) y = idealhnf_shallow(nf,y);
    1716     1228546 :   return gc_bool(av, ZM_equal(y,z));
    1717             : }
    1718             : static GEN
    1719     1392550 : ZV_divrem(GEN A, GEN B, GEN *pR)
    1720             : {
    1721     1392550 :   long i, l = lg(A);
    1722     1392550 :   GEN Q = cgetg(l, t_COL), R = cgetg(l, t_COL);
    1723     1899433 :   for (i = 1; i < l; i++) gel(Q,i) = truedvmdii(gel(A,i), gel(B,i), &gel(R,i));
    1724     1392549 :   *pR = R; return Q;
    1725             : }
    1726             : 
    1727             : static GEN
    1728     1392549 : Ur_ZC_mul(GEN bnf, GEN v)
    1729             : {
    1730     1392549 :   GEN w, U = bnf_get_Ur(bnf);
    1731     1392549 :   long i, l = lg(bnf_get_cyc(bnf)); /* may be < lgcols(U) */
    1732             : 
    1733     1392549 :   w = cgetg(l, t_COL);
    1734     1899435 :   for (i = 1; i < l; i++) gel(w,i) = ZMrow_ZC_mul(U, v, i);
    1735     1392551 :   return w;
    1736             : }
    1737             : 
    1738             : static GEN
    1739        7325 : ZV_mul(GEN x, GEN y)
    1740             : {
    1741        7325 :   long i, l = lg(x);
    1742        7325 :   GEN z = cgetg(l, t_COL);
    1743       31948 :   for (i = 1; i < l; i++) gel(z,i) = mulii(gel(x,i), gel(y,i));
    1744        7325 :   return z;
    1745             : }
    1746             : static int
    1747     1228033 : dump_gen(GEN SUnits, GEN x, long flag)
    1748             : {
    1749             :   GEN d;
    1750             :   long e;
    1751     1228033 :   if (!(flag & nf_GENMAT) || !SUnits) return 0;
    1752      272953 :   e = gexpo(gel(SUnits,2)); if (e > 64) return 0; /* U large */
    1753      272857 :   x = Q_remove_denom(x, &d);
    1754      272855 :   return (d && expi(d) > 32) || gexpo(x) > 32;
    1755             : }
    1756             : 
    1757             : /* assume x in HNF; cf class_group_gen for notations. Return NULL iff
    1758             :  * flag & nf_FORCE and computation of principal ideal generator fails */
    1759             : static GEN
    1760     1408721 : isprincipalall(GEN bnf, GEN x, long *pprec, long flag)
    1761             : {
    1762             :   GEN xar, Wex, Bex, gen, xc, col, A, Q, R, UA, SUnits;
    1763     1408721 :   GEN C = bnf_get_C(bnf), nf = bnf_get_nf(bnf), cyc = bnf_get_cyc(bnf);
    1764             :   long nB, nW, e;
    1765             : 
    1766     1408721 :   if (lg(cyc) == 1 && !(flag & (nf_GEN|nf_GENMAT|nf_GEN_IF_PRINCIPAL)))
    1767        4732 :     return cgetg(1,t_COL);
    1768     1403989 :   if (lg(x) == 2)
    1769             :   { /* nf = Q */
    1770          84 :     col = gel(x,1);
    1771          84 :     if (flag & nf_GENMAT) col = Q_to_famat(gel(col,1));
    1772          84 :     return (flag & nf_GEN_IF_PRINCIPAL)? col: mkvec2(cgetg(1,t_COL), col);
    1773             :   }
    1774             : 
    1775     1403905 :   x = Q_primitive_part(x, &xc);
    1776     1403903 :   if (equali1(gcoeff(x,1,1))) /* trivial ideal */
    1777             :   {
    1778       11354 :     R = zerocol(lg(cyc)-1);
    1779       11354 :     if (!(flag & (nf_GEN|nf_GENMAT|nf_GEN_IF_PRINCIPAL))) return R;
    1780       11305 :     if (flag & nf_GEN_IF_PRINCIPAL)
    1781        6468 :       return scalarcol_shallow(xc? xc: gen_1, nf_get_degree(nf));
    1782        4837 :     if (flag & nf_GENMAT)
    1783        2191 :       col = xc? Q_to_famat(xc): trivial_fact();
    1784             :     else
    1785        2646 :       col = scalarcol_shallow(xc? xc: gen_1, nf_get_degree(nf));
    1786        4837 :     return mkvec2(R, col);
    1787             :   }
    1788     1392549 :   xar = split_ideal(bnf, x, &Wex, &Bex);
    1789             :   /* x = g_W Wex + g_B Bex + [xar] = g_W (Wex - B*Bex) + [xar] + [C_B]Bex */
    1790     1392549 :   A = zc_to_ZC(Wex); nB = lg(Bex)-1;
    1791     1392549 :   if (nB) A = ZC_sub(A, ZM_zc_mul(bnf_get_B(bnf), Bex));
    1792     1392549 :   UA = Ur_ZC_mul(bnf, A);
    1793     1392550 :   Q = ZV_divrem(UA, cyc, &R);
    1794             :   /* g_W (Wex - B*Bex) = G Ur A - [ga]A = G R + [GD]Q - [ga]A
    1795             :    * Finally: x = G R + [xar] + [C_B]Bex + [GD]Q - [ga]A */
    1796     1392549 :   if (!(flag & (nf_GEN|nf_GENMAT|nf_GEN_IF_PRINCIPAL))) return R;
    1797     1232078 :   if ((flag & nf_GEN_IF_PRINCIPAL) && !ZV_equal0(R)) return gen_0;
    1798             : 
    1799     1232071 :   nW = lg(Wex)-1;
    1800     1232071 :   gen = bnf_get_gen(bnf);
    1801     1232071 :   col = NULL;
    1802     1232071 :   SUnits = bnf_get_sunits(bnf);
    1803     1232071 :   if (lg(R) == 1
    1804      272424 :       || abscmpiu(gel(R,vecindexmax(R)), 4 * (*pprec)) < 0)
    1805             :   { /* q = N (x / prod gj^ej) = N(alpha), denom(alpha) | d */
    1806     1231474 :     GEN d, q = gdiv(ZM_det_triangular(x), get_norm_fact(gen, R, &d));
    1807     1231476 :     col = xar? nf_cxlog(nf, xar, *pprec): NULL;
    1808     1231476 :     if (nB) col = add(col, act_arch(Bex, nW? vecslice(C,nW+1,lg(C)-1): C));
    1809     1231472 :     if (nW) col = add(col, RgC_sub(act_arch(Q, bnf_get_GD(bnf)),
    1810             :                                    act_arch(A, bnf_get_ga(bnf))));
    1811     1231472 :     col = isprincipalarch(bnf, col, q, gen_1, d, &e);
    1812     1231476 :     if (col && (dump_gen(SUnits, col, flag)
    1813     1228031 :                 || !fact_ok(nf,x, col,gen,R))) col = NULL;
    1814             :   }
    1815     1232069 :   if (!col && (flag & nf_GENMAT))
    1816             :   {
    1817        8066 :     if (SUnits)
    1818             :     {
    1819        7577 :       GEN X = gel(SUnits,1), U = gel(SUnits,2), C = gel(SUnits,3);
    1820        7577 :       GEN v = gel(bnf,9), Ge = gel(v,4), M1 = gel(v,5), M2 = gel(v,6);
    1821        7577 :       GEN z = NULL, F = NULL;
    1822        7577 :       if (nB)
    1823             :       {
    1824        7577 :         GEN C2 = nW? vecslice(C, nW+1, lg(C)-1): C;
    1825        7577 :         z = ZM_zc_mul(C2, Bex);
    1826             :       }
    1827        7577 :       if (nW)
    1828             :       { /* [GD]Q - [ga]A = ([X]M1 - [Ge]D) Q - ([X]M2 - [Ge]Ur) A */
    1829        7325 :         GEN C1 = vecslice(C, 1, nW);
    1830        7325 :         GEN v = ZC_sub(ZM_ZC_mul(M1,Q), ZM_ZC_mul(M2,A));
    1831        7325 :         z = add(z, ZM_ZC_mul(C1, v));
    1832        7325 :         F = famat_reduce(famatV_factorback(Ge, ZC_sub(UA, ZV_mul(cyc,Q))));
    1833        7325 :         if (lgcols(F) == 1) F = NULL;
    1834             :       }
    1835             :       /* reduce modulo units and Q^* */
    1836        7577 :       if (lg(U) != 1) z = ZC_sub(z, ZM_ZC_mul(U, RgM_Babai(U,z)));
    1837        7577 :       col = mkmat2(X, z);
    1838        7577 :       if (F) col = famat_mul_shallow(col, F);
    1839        7577 :       col = famat_remove_trivial(col);
    1840        7577 :       if (xar) col = famat_mul_shallow(col, xar);
    1841             :     }
    1842         489 :     else if (!ZV_equal0(R))
    1843             :     { /* in case isprincipalfact calls bnfinit() due to prec trouble...*/
    1844         483 :       GEN y = isprincipalfact(bnf, x, gen, ZC_neg(R), flag);
    1845         483 :       if (typ(y) != t_VEC) return y;
    1846         483 :       col = gel(y,2);
    1847             :     }
    1848             :   }
    1849     1232069 :   if (col)
    1850             :   { /* add back missing content */
    1851     1231979 :     if (typ(col) == t_MAT)
    1852        8060 :     { if (xc) col = famat_mul_shallow(col, xc); }
    1853     1223919 :     else if (flag & nf_GENMAT)
    1854             :     {
    1855             :       GEN c;
    1856     1210220 :       if (RgV_isscalar(col))
    1857        3651 :         col = Q_to_famat(mul_content(xc, gel(col,1)));
    1858             :       else
    1859             :       {
    1860     1206568 :         col = Q_primitive_part(col, &c);
    1861     1206569 :         col = to_famat_shallow(col, gen_1);
    1862     1206570 :         xc = mul_content(xc, c);
    1863     1206570 :         if (xc) col = famat_mul(col, Q_to_famat(xc));
    1864             :       }
    1865             :     }
    1866             :     else
    1867       13699 :     { if (xc) col = RgC_Rg_mul(col,xc); }
    1868             :   }
    1869             :   else
    1870             :   {
    1871          90 :     if (e < 0) e = 0;
    1872          90 :     *pprec += nbits2extraprec(e + 128);
    1873          90 :     if (flag & nf_FORCE)
    1874             :     {
    1875          76 :       if (DEBUGLEVEL)
    1876           0 :         pari_warn(warner,"precision too low for generators, e = %ld",e);
    1877          76 :       return NULL;
    1878             :     }
    1879          14 :     pari_warn(warner,"precision too low for generators, not given");
    1880          14 :     col = cgetg(1, t_COL);
    1881             :   }
    1882     1231995 :   return (flag & nf_GEN_IF_PRINCIPAL)? col: mkvec2(R, col);
    1883             : }
    1884             : 
    1885             : static GEN
    1886      464660 : triv_gen(GEN bnf, GEN x, long flag)
    1887             : {
    1888      464660 :   pari_sp av = avma;
    1889      464660 :   GEN nf = bnf_get_nf(bnf);
    1890             :   long c;
    1891      464660 :   if (flag & nf_GEN_IF_PRINCIPAL)
    1892             :   {
    1893           7 :     if (!(flag & nf_GENMAT)) return algtobasis(nf,x);
    1894           7 :     x = nf_to_scalar_or_basis(nf,x);
    1895           7 :     if (typ(x) == t_INT && is_pm1(x)) return trivial_fact();
    1896           0 :     return gc_GEN(av, to_famat_shallow(x, gen_1));
    1897             :   }
    1898      464653 :   c = lg(bnf_get_cyc(bnf)) - 1;
    1899      464653 :   if (flag & nf_GENMAT)
    1900      455049 :     retmkvec2(zerocol(c), to_famat_shallow(algtobasis(nf,x), gen_1));
    1901        9604 :   if (flag & nf_GEN)
    1902          28 :     retmkvec2(zerocol(c), algtobasis(nf,x));
    1903        9576 :   return zerocol(c);
    1904             : }
    1905             : 
    1906             : GEN
    1907     1841332 : bnfisprincipal0(GEN bnf,GEN x,long flag)
    1908             : {
    1909     1841332 :   pari_sp av = avma;
    1910             :   GEN c, nf;
    1911             :   long pr;
    1912             : 
    1913     1841332 :   bnf = checkbnf(bnf);
    1914     1841333 :   nf = bnf_get_nf(bnf);
    1915     1841333 :   switch( idealtyp(&x, NULL) )
    1916             :   {
    1917       59080 :     case id_PRINCIPAL:
    1918       59080 :       if (gequal0(x)) pari_err_DOMAIN("bnfisprincipal","ideal","=",gen_0,x);
    1919       59080 :       return triv_gen(bnf, x, flag);
    1920     1758592 :     case id_PRIME:
    1921     1758592 :       if (pr_is_inert(x)) return triv_gen(bnf, pr_get_p(x), flag);
    1922     1353019 :       x = pr_hnf(nf, x);
    1923     1353022 :       break;
    1924       23660 :     case id_MAT:
    1925       23660 :       if (lg(x)==1) pari_err_DOMAIN("bnfisprincipal","ideal","=",gen_0,x);
    1926       23660 :       if (nf_get_degree(nf) != lg(x)-1)
    1927           0 :         pari_err_TYPE("idealtyp [dimension != degree]", x);
    1928             :   }
    1929     1376683 :   pr = prec_arch(bnf); /* precision of unit matrix */
    1930     1376681 :   c = getrand();
    1931             :   for (;;)
    1932           6 :   {
    1933     1376688 :     pari_sp av1 = avma;
    1934     1376688 :     GEN y = isprincipalall(bnf,x,&pr,flag);
    1935     1376686 :     if (y) return gc_GEN(av, y);
    1936             : 
    1937           6 :     if (DEBUGLEVEL) pari_warn(warnprec,"isprincipal",pr);
    1938           6 :     set_avma(av1); bnf = bnfnewprec_shallow(bnf,pr); setrand(c);
    1939             :   }
    1940             : }
    1941             : GEN
    1942      174779 : isprincipal(GEN bnf,GEN x) { return bnfisprincipal0(bnf,x,0); }
    1943             : 
    1944             : /* FIXME: OBSOLETE */
    1945             : GEN
    1946           0 : isprincipalgen(GEN bnf,GEN x)
    1947           0 : { return bnfisprincipal0(bnf,x,nf_GEN); }
    1948             : GEN
    1949           0 : isprincipalforce(GEN bnf,GEN x)
    1950           0 : { return bnfisprincipal0(bnf,x,nf_FORCE); }
    1951             : GEN
    1952           0 : isprincipalgenforce(GEN bnf,GEN x)
    1953           0 : { return bnfisprincipal0(bnf,x,nf_GEN | nf_FORCE); }
    1954             : 
    1955             : /* lg(u) > 1 */
    1956             : static int
    1957         105 : RgV_is1(GEN u) { return isint1(gel(u,1)) && RgV_isscalar(u); }
    1958             : static GEN
    1959       31963 : add_principal_part(GEN nf, GEN u, GEN v, long flag)
    1960             : {
    1961       31963 :   if (flag & nf_GENMAT)
    1962       14540 :     return (typ(u) == t_COL && RgV_is1(u))? v: famat_mul_shallow(v,u);
    1963             :   else
    1964       17423 :     return nfmul(nf, v, u);
    1965             : }
    1966             : 
    1967             : #if 0
    1968             : /* compute C prod P[i]^e[i],  e[i] >=0 for all i. C may be NULL (omitted)
    1969             :  * e destroyed ! */
    1970             : static GEN
    1971             : expand(GEN nf, GEN C, GEN P, GEN e)
    1972             : {
    1973             :   long i, l = lg(e), done = 1;
    1974             :   GEN id = C;
    1975             :   for (i=1; i<l; i++)
    1976             :   {
    1977             :     GEN ei = gel(e,i);
    1978             :     if (signe(ei))
    1979             :     {
    1980             :       if (mod2(ei)) id = id? idealmul(nf, id, gel(P,i)): gel(P,i);
    1981             :       ei = shifti(ei,-1);
    1982             :       if (signe(ei)) done = 0;
    1983             :       gel(e,i) = ei;
    1984             :     }
    1985             :   }
    1986             :   if (id != C) id = idealred(nf, id);
    1987             :   if (done) return id;
    1988             :   return idealmulred(nf, id, idealsqr(nf, expand(nf,id,P,e)));
    1989             : }
    1990             : /* C is an extended ideal, possibly with C[1] = NULL */
    1991             : static GEN
    1992             : expandext(GEN nf, GEN C, GEN P, GEN e)
    1993             : {
    1994             :   long i, l = lg(e), done = 1;
    1995             :   GEN A = gel(C,1);
    1996             :   for (i=1; i<l; i++)
    1997             :   {
    1998             :     GEN ei = gel(e,i);
    1999             :     if (signe(ei))
    2000             :     {
    2001             :       if (mod2(ei)) A = A? idealmul(nf, A, gel(P,i)): gel(P,i);
    2002             :       ei = shifti(ei,-1);
    2003             :       if (signe(ei)) done = 0;
    2004             :       gel(e,i) = ei;
    2005             :     }
    2006             :   }
    2007             :   if (A == gel(C,1))
    2008             :     A = C;
    2009             :   else
    2010             :     A = idealred(nf, mkvec2(A, gel(C,2)));
    2011             :   if (done) return A;
    2012             :   return idealmulred(nf, A, idealsqr(nf, expand(nf,A,P,e)));
    2013             : }
    2014             : #endif
    2015             : 
    2016             : static GEN
    2017           0 : expand(GEN nf, GEN C, GEN P, GEN e)
    2018             : {
    2019           0 :   long i, l = lg(e);
    2020           0 :   GEN B, A = C;
    2021           0 :   for (i=1; i<l; i++) /* compute prod P[i]^e[i] */
    2022           0 :     if (signe(gel(e,i)))
    2023             :     {
    2024           0 :       B = idealpowred(nf, gel(P,i), gel(e,i));
    2025           0 :       A = A? idealmulred(nf,A,B): B;
    2026             :     }
    2027           0 :   return A;
    2028             : }
    2029             : static GEN
    2030       31984 : expandext(GEN nf, GEN C, GEN P, GEN e)
    2031             : {
    2032       31984 :   long i, l = lg(e);
    2033       31984 :   GEN B, A = gel(C,1), C1 = A;
    2034       94800 :   for (i=1; i<l; i++) /* compute prod P[i]^e[i] */
    2035       62816 :     if (signe(gel(e,i)))
    2036             :     {
    2037       35006 :       gel(C,1) = gel(P,i);
    2038       35006 :       B = idealpowred(nf, C, gel(e,i));
    2039       35006 :       A = A? idealmulred(nf,A,B): B;
    2040             :     }
    2041       31984 :   return A == C1? C: A;
    2042             : }
    2043             : 
    2044             : /* isprincipal for C * \prod P[i]^e[i] (C omitted if NULL) */
    2045             : GEN
    2046       31984 : isprincipalfact(GEN bnf, GEN C, GEN P, GEN e, long flag)
    2047             : {
    2048       31984 :   const long gen = flag & (nf_GEN|nf_GENMAT|nf_GEN_IF_PRINCIPAL);
    2049             :   long prec;
    2050       31984 :   pari_sp av = avma;
    2051       31984 :   GEN C0, Cext, c, id, nf = bnf_get_nf(bnf);
    2052             : 
    2053       31984 :   if (gen)
    2054             :   {
    2055       14547 :     Cext = (flag & nf_GENMAT)? trivial_fact()
    2056       31984 :                              : mkpolmod(gen_1,nf_get_pol(nf));
    2057       31984 :     C0 = mkvec2(C, Cext);
    2058       31984 :     id = expandext(nf, C0, P, e);
    2059             :   } else {
    2060           0 :     Cext = NULL;
    2061           0 :     C0 = C;
    2062           0 :     id = expand(nf, C, P, e);
    2063             :   }
    2064       31984 :   if (id == C0) /* e = 0 */
    2065             :   {
    2066       12477 :     if (!C) return bnfisprincipal0(bnf, gen_1, flag);
    2067       12463 :     switch(typ(C))
    2068             :     {
    2069           7 :       case t_INT: case t_FRAC: case t_POL: case t_POLMOD: case t_COL:
    2070           7 :         return triv_gen(bnf, C, flag);
    2071             :     }
    2072       12456 :     C = idealhnf_shallow(nf,C);
    2073             :   }
    2074             :   else
    2075             :   {
    2076       19507 :     if (gen) { C = gel(id,1); Cext = gel(id,2); } else C = id;
    2077             :   }
    2078       31963 :   prec = prec_arch(bnf);
    2079       31963 :   c = getrand();
    2080             :   for (;;)
    2081          70 :   {
    2082       32033 :     pari_sp av1 = avma;
    2083       32033 :     GEN y = isprincipalall(bnf, C, &prec, flag);
    2084       32033 :     if (y)
    2085             :     {
    2086       31963 :       if (flag & nf_GEN_IF_PRINCIPAL)
    2087             :       {
    2088       20818 :         if (typ(y) == t_INT) return gc_NULL(av);
    2089       20818 :         y = add_principal_part(nf, y, Cext, flag);
    2090             :       }
    2091             :       else
    2092             :       {
    2093       11145 :         GEN u = gel(y,2);
    2094       11145 :         if (!gen || typ(y) != t_VEC) return gc_upto(av,y);
    2095       11145 :         if (lg(u) != 1) gel(y,2) = add_principal_part(nf, u, Cext, flag);
    2096             :       }
    2097       31962 :       return gc_GEN(av, y);
    2098             :     }
    2099          70 :     if (DEBUGLEVEL) pari_warn(warnprec,"isprincipal",prec);
    2100          70 :     set_avma(av1); bnf = bnfnewprec_shallow(bnf,prec); setrand(c);
    2101             :   }
    2102             : }
    2103             : GEN
    2104           0 : isprincipalfact_or_fail(GEN bnf, GEN C, GEN P, GEN e)
    2105             : {
    2106           0 :   const long flag = nf_GENMAT|nf_FORCE;
    2107             :   long prec;
    2108           0 :   pari_sp av = avma;
    2109           0 :   GEN u, y, id, C0, Cext, nf = bnf_get_nf(bnf);
    2110             : 
    2111           0 :   Cext = trivial_fact();
    2112           0 :   C0 = mkvec2(C, Cext);
    2113           0 :   id = expandext(nf, C0, P, e);
    2114           0 :   if (id == C0) /* e = 0 */
    2115           0 :     C = idealhnf_shallow(nf,C);
    2116             :   else {
    2117           0 :     C = gel(id,1); Cext = gel(id,2);
    2118             :   }
    2119           0 :   prec = prec_arch(bnf);
    2120           0 :   y = isprincipalall(bnf, C, &prec, flag);
    2121           0 :   if (!y) return gc_utoipos(av, prec);
    2122           0 :   u = gel(y,2);
    2123           0 :   if (lg(u) != 1) gel(y,2) = add_principal_part(nf, u, Cext, flag);
    2124           0 :   return gc_GEN(av, y);
    2125             : }
    2126             : 
    2127             : GEN
    2128      162325 : nfsign_from_logarch(GEN LA, GEN invpi, GEN archp)
    2129             : {
    2130      162325 :   long l = lg(archp), i;
    2131      162325 :   GEN y = cgetg(l, t_VECSMALL);
    2132      162327 :   pari_sp av = avma;
    2133             : 
    2134      310066 :   for (i=1; i<l; i++)
    2135             :   {
    2136      147738 :     GEN c = ground( gmul(imag_i(gel(LA,archp[i])), invpi) );
    2137      147741 :     y[i] = mpodd(c)? 1: 0;
    2138             :   }
    2139      162328 :   set_avma(av); return y;
    2140             : }
    2141             : 
    2142             : GEN
    2143      239979 : nfsign_tu(GEN bnf, GEN archp)
    2144             : {
    2145             :   long n;
    2146      239979 :   if (bnf_get_tuN(bnf) != 2) return cgetg(1, t_VECSMALL);
    2147      172876 :   n = archp? lg(archp) - 1: nf_get_r1(bnf_get_nf(bnf));
    2148      172876 :   return const_vecsmall(n, 1);
    2149             : }
    2150             : GEN
    2151      241155 : nfsign_fu(GEN bnf, GEN archp)
    2152             : {
    2153      241155 :   GEN invpi, y, A = bnf_get_logfu(bnf), nf = bnf_get_nf(bnf);
    2154      241155 :   long j = 1, RU = lg(A);
    2155             : 
    2156      241155 :   if (!archp) archp = identity_perm( nf_get_r1(nf) );
    2157      241155 :   invpi = invr( mppi(nf_get_prec(nf)) );
    2158      241150 :   y = cgetg(RU,t_MAT);
    2159      403388 :   for (j = 1; j < RU; j++)
    2160      162227 :     gel(y,j) = nfsign_from_logarch(gel(A,j), invpi, archp);
    2161      241161 :   return y;
    2162             : }
    2163             : GEN
    2164          35 : nfsign_units(GEN bnf, GEN archp, int add_zu)
    2165             : {
    2166          35 :   GEN sfu = nfsign_fu(bnf, archp);
    2167          35 :   return add_zu? vec_prepend(sfu, nfsign_tu(bnf, archp)): sfu;
    2168             : }
    2169             : 
    2170             : /* obsolete */
    2171             : GEN
    2172           7 : signunits(GEN bnf)
    2173             : {
    2174             :   pari_sp av;
    2175             :   GEN S, y, nf;
    2176             :   long i, j, r1, r2;
    2177             : 
    2178           7 :   bnf = checkbnf(bnf); nf = bnf_get_nf(bnf);
    2179           7 :   nf_get_sign(nf, &r1,&r2);
    2180           7 :   S = zeromatcopy(r1, r1+r2-1); av = avma;
    2181           7 :   y = nfsign_fu(bnf, NULL);
    2182          14 :   for (j = 1; j < lg(y); j++)
    2183             :   {
    2184           7 :     GEN Sj = gel(S,j), yj = gel(y,j);
    2185          21 :     for (i = 1; i <= r1; i++) gel(Sj,i) = yj[i]? gen_m1: gen_1;
    2186             :   }
    2187           7 :   set_avma(av); return S;
    2188             : }
    2189             : 
    2190             : static GEN
    2191      726091 : get_log_embed(REL_t *rel, GEN M, long RU, long R1, long prec)
    2192             : {
    2193      726091 :   GEN arch, C, z = rel->m;
    2194             :   long i;
    2195      726091 :   arch = typ(z) == t_COL? RgM_RgC_mul(M, z): const_col(nbrows(M), z);
    2196      726098 :   C = cgetg(RU+1, t_COL); arch = glog(arch, prec);
    2197     1654551 :   for (i=1; i<=R1; i++) gel(C,i) = gel(arch,i);
    2198     1565321 :   for (   ; i<=RU; i++) gel(C,i) = gmul2n(gel(arch,i), 1);
    2199      726079 :   return C;
    2200             : }
    2201             : static GEN
    2202     1017064 : rel_embed(REL_t *rel, FB_t *F, GEN embs, long ind, GEN M, long RU, long R1,
    2203             :           long prec)
    2204             : {
    2205             :   GEN C, D, perm;
    2206             :   long i, n;
    2207     1017064 :   if (!rel->relaut) return get_log_embed(rel, M, RU, R1, prec);
    2208             :   /* image of another relation by automorphism */
    2209      290973 :   C = gel(embs, ind - rel->relorig);
    2210      290973 :   perm = gel(F->embperm, rel->relaut);
    2211      290973 :   D = cgetg_copy(C, &n);
    2212     1217812 :   for (i = 1; i < n; i++)
    2213             :   {
    2214      926831 :     long v = perm[i];
    2215      926831 :     gel(D,i) = (v > 0)? gel(C,v): conj_i(gel(C,-v));
    2216             :   }
    2217      290981 :   return D;
    2218             : }
    2219             : static GEN
    2220      122410 : get_embs(FB_t *F, RELCACHE_t *cache, GEN nf, GEN embs, long PREC)
    2221             : {
    2222      122410 :   long ru, j, k, l = cache->last - cache->chk + 1, r1 = nf_get_r1(nf);
    2223      122410 :   GEN M = nf_get_M(nf), nembs = cgetg(cache->last - cache->base+1, t_MAT);
    2224             :   REL_t *rel;
    2225             : 
    2226     1517102 :   for (k = 1; k <= cache->chk - cache->base; k++) gel(nembs,k) = gel(embs,k);
    2227      122409 :   embs = nembs; ru = nbrows(M);
    2228     1126890 :   for (j=1,rel = cache->chk + 1; j < l; rel++,j++,k++)
    2229     1004488 :     gel(embs,k) = rel_embed(rel, F, embs, k, M, ru, r1, PREC);
    2230      122402 :   return embs;
    2231             : }
    2232             : static void
    2233      948646 : set_rel_alpha(REL_t *rel, GEN auts, GEN vA, long ind)
    2234             : {
    2235             :   GEN u;
    2236      948646 :   if (!rel->relaut)
    2237      674823 :     u = rel->m;
    2238             :   else
    2239      273823 :     u = ZM_ZC_mul(gel(auts, rel->relaut), gel(vA, ind - rel->relorig));
    2240      948643 :   gel(vA, ind) = u;
    2241      948643 : }
    2242             : static GEN
    2243     2315386 : set_fact(FB_t *F, FACT *fact, GEN e, long *pnz)
    2244             : {
    2245     2315386 :   long i, n = fact[0].pr, nz = F->KC + 1;
    2246     2315386 :   GEN c = zero_Flv(F->KC);
    2247    10861413 :   for (i = 1; i <= n; i++)
    2248             :   {
    2249     8546022 :     long p = fact[i].pr;
    2250     8546022 :     if (p < nz) nz = p;
    2251     8546022 :     c[p] = fact[i].ex;
    2252             :   }
    2253     2315391 :   if (e)
    2254             :   {
    2255      114517 :     long l = lg(e);
    2256      334252 :     for (i = 1; i < l; i++)
    2257      219735 :       if (e[i]) { long v = F->subFB[i]; c[v] += e[i]; if (v < nz) nz = v; }
    2258             :   }
    2259     2315391 :   *pnz = nz; return c;
    2260             : }
    2261             : 
    2262             : /* Is cols already in the cache ? bs = index of first non zero coeff in cols
    2263             :  * General check for colinearity useless since exceedingly rare */
    2264             : static int
    2265     2968710 : already_known(RELCACHE_t *cache, long bs, GEN cols)
    2266             : {
    2267             :   REL_t *r;
    2268     2968710 :   long l = lg(cols);
    2269   220206453 :   for (r = cache->last; r > cache->base; r--)
    2270   217727466 :     if (bs == r->nz)
    2271             :     {
    2272    34413572 :       GEN coll = r->R;
    2273    34413572 :       long b = bs;
    2274   124138000 :       while (b < l && cols[b] == coll[b]) b++;
    2275    34413572 :       if (b == l) return 1;
    2276             :     }
    2277     2478987 :   return 0;
    2278             : }
    2279             : 
    2280             : /* Add relation R to cache, nz = index of first non zero coeff in R.
    2281             :  * If relation is a linear combination of the previous ones, return 0.
    2282             :  * Otherwise, update basis and return > 0. Compute mod p (much faster)
    2283             :  * so some kernel vector might not be genuine. */
    2284             : static int
    2285     2972852 : add_rel_i(RELCACHE_t *cache, GEN R, long nz, GEN m, long orig, long aut, REL_t **relp, long in_rnd_rel)
    2286             : {
    2287     2972852 :   long i, k, n = lg(R)-1;
    2288             : 
    2289     2972852 :   if (nz == n+1) { k = 0; goto ADD_REL; }
    2290     2968705 :   if (already_known(cache, nz, R)) return -1;
    2291     2479042 :   if (cache->last >= cache->base + cache->len) return 0;
    2292     2479042 :   if (DEBUGLEVEL>6)
    2293             :   {
    2294           0 :     err_printf("adding vector = %Ps\n",R);
    2295           0 :     err_printf("generators =\n%Ps\n", cache->basis);
    2296             :   }
    2297     2479059 :   if (cache->missing)
    2298             :   {
    2299     2082767 :     GEN a = leafcopy(R), basis = cache->basis;
    2300     2082763 :     k = lg(a);
    2301   127975974 :     do --k; while (!a[k]);
    2302     7310661 :     while (k)
    2303             :     {
    2304     5697540 :       GEN c = gel(basis, k);
    2305     5697540 :       if (c[k])
    2306             :       {
    2307     5227898 :         long ak = a[k];
    2308   269126373 :         for (i=1; i < k; i++) if (c[i]) a[i] = (a[i] + ak*(mod_p-c[i])) % mod_p;
    2309     5227898 :         a[k] = 0;
    2310   132735985 :         do --k; while (!a[k]); /* k cannot go below 0: codeword is a sentinel */
    2311             :       }
    2312             :       else
    2313             :       {
    2314      469642 :         ulong invak = Fl_inv(uel(a,k), mod_p);
    2315             :         /* Cleanup a */
    2316    14002440 :         for (i = k; i-- > 1; )
    2317             :         {
    2318    13532798 :           long j, ai = a[i];
    2319    13532798 :           c = gel(basis, i);
    2320    13532798 :           if (!ai || !c[i]) continue;
    2321      237847 :           ai = mod_p-ai;
    2322     4508750 :           for (j = 1; j < i; j++) if (c[j]) a[j] = (a[j] + ai*c[j]) % mod_p;
    2323      237847 :           a[i] = 0;
    2324             :         }
    2325             :         /* Insert a/a[k] as k-th column */
    2326      469642 :         c = gel(basis, k);
    2327    14002441 :         for (i = 1; i<k; i++) if (a[i]) c[i] = (a[i] * invak) % mod_p;
    2328      469642 :         c[k] = 1; a = c;
    2329             :         /* Cleanup above k */
    2330    13796494 :         for (i = k+1; i<n; i++)
    2331             :         {
    2332             :           long j, ck;
    2333    13326852 :           c = gel(basis, i);
    2334    13326852 :           ck = c[k];
    2335    13326852 :           if (!ck) continue;
    2336     2764952 :           ck = mod_p-ck;
    2337   100012552 :           for (j = 1; j < k; j++) if (a[j]) c[j] = (c[j] + ck*a[j]) % mod_p;
    2338     2764952 :           c[k] = 0;
    2339             :         }
    2340      469642 :         cache->missing--;
    2341      469642 :         break;
    2342             :       }
    2343             :     }
    2344             :   }
    2345             :   else
    2346      396292 :     k = (cache->last - cache->base) + 1;
    2347     2479055 :   if (k || cache->relsup > 0 || (m && in_rnd_rel))
    2348             :   {
    2349             :     REL_t *rel;
    2350             : 
    2351      989128 : ADD_REL:
    2352      993275 :     rel = ++cache->last;
    2353      993275 :     if (!k && cache->relsup && nz < n+1)
    2354             :     {
    2355      122849 :       cache->relsup--;
    2356      122849 :       k = (rel - cache->base) + cache->missing;
    2357             :     }
    2358      993275 :     rel->R  = gclone(R);
    2359      993285 :     rel->m  = m ? gclone(m) : NULL;
    2360      993277 :     rel->nz = nz;
    2361      993277 :     if (aut)
    2362             :     {
    2363      288377 :       rel->relorig = (rel - cache->base) - orig;
    2364      288377 :       rel->relaut = aut;
    2365             :     }
    2366             :     else
    2367      704900 :       rel->relaut = 0;
    2368      993277 :     if (relp) *relp = rel;
    2369      993277 :     if (DEBUGLEVEL) dbg_newrel(cache);
    2370             :   }
    2371     2483200 :   return k;
    2372             : }
    2373             : 
    2374             : /* m a t_INT or primitive t_COL */
    2375             : static int
    2376     2488410 : add_rel(RELCACHE_t *cache, FB_t *F, GEN R, long nz, GEN m, long in_rnd_rel)
    2377             : {
    2378             :   REL_t *rel;
    2379             :   long k, l, reln;
    2380     2488410 :   const long lauts = lg(F->idealperm), KC = F->KC;
    2381             : 
    2382     2488410 :   k = add_rel_i(cache, R, nz, m, 0, 0, &rel, in_rnd_rel);
    2383     2488463 :   if (k > 0 && typ(m) != t_INT)
    2384             :   {
    2385      531393 :     GEN Rl = cgetg(KC+1, t_VECSMALL);
    2386      531395 :     reln = rel - cache->base;
    2387     1015855 :     for (l = 1; l < lauts; l++)
    2388             :     {
    2389      484452 :       GEN perml = gel(F->idealperm, l);
    2390      484452 :       long i, nzl = perml[nz];
    2391             : 
    2392    20547061 :       for (i = 1; i <= KC; i++) Rl[i] = 0;
    2393    18319287 :       for (i = nz; i <= KC; i++)
    2394    17834835 :         if (R[i])
    2395             :         {
    2396     1288183 :           long v = perml[i];
    2397             : 
    2398     1288183 :           if (v < nzl) nzl = v;
    2399     1288183 :           Rl[v] = R[i];
    2400             :         }
    2401      484452 :       (void)add_rel_i(cache, Rl, nzl, NULL, reln, l, NULL, in_rnd_rel);
    2402             :     }
    2403             :   }
    2404     2488473 :   return k;
    2405             : }
    2406             : 
    2407             : INLINE void
    2408    28415394 : step(GEN x, double *y, GEN inc, long k)
    2409             : {
    2410    28415394 :   if (!y[k])
    2411     2228806 :     x[k]++; /* leading coeff > 0 */
    2412             :   else
    2413             :   {
    2414    26186588 :     long i = inc[k];
    2415    26186588 :     x[k] += i;
    2416    26186588 :     inc[k] = (i > 0)? -1-i: 1-i;
    2417             :   }
    2418    28415394 : }
    2419             : 
    2420             : /* degree n >= 2 */
    2421             : static double
    2422      266571 : Fincke_Pohst_bound(double T, GEN r)
    2423             : {
    2424      266571 :   pari_sp av = avma;
    2425      266571 :   GEN zT = dbltor(T * T), p = gmael(r,1,1), B = NULL;
    2426      266564 :   long i, n = lg(r)-1;
    2427      266564 :   double g = 0.;
    2428      611379 :   for (i = 2; i <= n; i++)
    2429             :   {
    2430      611365 :     p = gmul(p, gmael(r,i,i));
    2431      611388 :     B = sqrtnr(gmul(zT,p), i);
    2432      611372 :     if (i == n || cmprr(B, gmael(r,i+1,i+1)) < 0) break;
    2433             :   }
    2434      266574 :   if (!gisdouble(B,&g)) g = 0.;
    2435      266565 :   return gc_double(av, g);
    2436             : }
    2437             : 
    2438             : static void
    2439     2052113 : fact_update(GEN R, FB_t *F, long ipr, GEN c)
    2440             : {
    2441     2052113 :   GEN pr = gel(F->LP,ipr), p = pr_get_p(pr);
    2442     2052111 :   long v = Z_lval(c, itou(p));
    2443     2052127 :   if (v) R[ipr] -= pr_get_e(pr) * v;
    2444     2052126 : }
    2445             : 
    2446             : static long
    2447      266572 : Fincke_Pohst_ideal_both(RELCACHE_t *cache, GEN V, FB_t *F, GEN nf, GEN I, GEN NI,
    2448             :   FACT *fact, long max_FACT, long Nrelid, FP_t *fp, GEN rex, long jid, long jid0, long e0,
    2449             :   long *Nsmall, long *Nfact)
    2450             : {
    2451             :   pari_sp av;
    2452      266572 :   GEN G = nf_get_G(nf), G0 = nf_get_roundG(nf), r, u, gx, cgx, inc, ideal;
    2453      266569 :   long prec = nf_get_prec(nf), N = nf_get_degree(nf);
    2454      266566 :   long j, k, skipfirst, relid = 0, try_factor = 0, rel = 1;
    2455      266566 :   long try_elt = 0, maxtry_ELEMENT = 4*max_FACT*max_FACT;
    2456             :   double BOUND, B1, B2;
    2457             : 
    2458      266566 :   inc = const_vecsmall(N, 1);
    2459      266565 :   u = ZM_lll(ZM_mul(G0, I), 0.99, LLL_IM);
    2460      266573 :   ideal = ZM_mul(I,u); /* approximate T2-LLL reduction */
    2461      266551 :   r = gaussred_from_QR(RgM_mul(G, ideal), prec); /* Cholesky for T2 | ideal */
    2462      266575 :   if (!r) pari_err_BUG("small_norm (precision too low)");
    2463             : 
    2464     1184216 :   for (k=1; k<=N; k++)
    2465             :   {
    2466      917645 :     if (!gisdouble(gcoeff(r,k,k),&(fp->v[k]))) return 0;
    2467     2724822 :     for (j=1; j<k; j++) if (!gisdouble(gcoeff(r,j,k),&(fp->q[j][k]))) return 0;
    2468      917641 :     if (DEBUGLEVEL>3) err_printf("v[%ld]=%.4g ",k,fp->v[k]);
    2469             :   }
    2470      266571 :   B1 = fp->v[1]; /* T2(ideal[1]) */
    2471      266571 :   B2 = fp->v[2] + B1 * fp->q[1][2] * fp->q[1][2]; /* T2(ideal[2]) */
    2472      266571 :   skipfirst = ZV_isscalar(gel(ideal,1));
    2473      266571 :   BOUND = maxdd(2*B2, Fincke_Pohst_bound(4 * max_FACT / F->ballvol, r));
    2474      266563 :   if (DEBUGLEVEL>1)
    2475             :   {
    2476           0 :     if (DEBUGLEVEL>3) err_printf("\n");
    2477           0 :     err_printf("BOUND = %.4g\n",BOUND);
    2478             :   }
    2479             : 
    2480      266564 :   k = N; fp->y[N] = fp->z[N] = 0; fp->x[N] = 0;
    2481    18816107 :   for (av = avma;; set_avma(av), step(fp->x,fp->y,inc,k))
    2482    18549192 :   {
    2483             :     GEN R;
    2484             :     long nz;
    2485             :     do
    2486             :     { /* look for primitive element of small norm, cf minim00 */
    2487    23670214 :       int fl = 0;
    2488             :       double p;
    2489    23670214 :       if (k > 1)
    2490             :       {
    2491     5121086 :         long l = k-1;
    2492     5121086 :         fp->z[l] = 0;
    2493    45542105 :         for (j=k; j<=N; j++) fp->z[l] += fp->q[l][j]*fp->x[j];
    2494     5121086 :         p = (double)fp->x[k] + fp->z[k];
    2495     5121086 :         fp->y[l] = fp->y[k] + p*p*fp->v[k];
    2496     5121086 :         if (l <= skipfirst && !fp->y[1]) fl = 1;
    2497     5121086 :         fp->x[l] = (long)floor(-fp->z[l] + 0.5);
    2498     5121086 :         k = l;
    2499             :       }
    2500     4476289 :       for(;; step(fp->x,fp->y,inc,k))
    2501             :       {
    2502    28146460 :         if (!fl)
    2503             :         {
    2504    28106878 :           if (++try_elt > maxtry_ELEMENT) goto END_Fincke_Pohst_ideal;
    2505    28104085 :           p = (double)fp->x[k] + fp->z[k];
    2506    28104085 :           if (fp->y[k] + p*p*fp->v[k] <= BOUND) break;
    2507             : 
    2508     5389828 :           step(fp->x,fp->y,inc,k);
    2509             : 
    2510     5390035 :           p = (double)fp->x[k] + fp->z[k];
    2511     5390035 :           if (fp->y[k] + p*p*fp->v[k] <= BOUND) break;
    2512             :         }
    2513     4479082 :         fl = 0; inc[k] = 1;
    2514     4479082 :         if (++k > N) goto END_Fincke_Pohst_ideal;
    2515             :       }
    2516    23667585 :     } while (k > 1);
    2517             : 
    2518             :     /* element complete */
    2519    33923847 :     if (zv_content(fp->x) !=1) continue; /* not primitive */
    2520    15662669 :     gx = ZM_zc_mul(ideal,fp->x);
    2521    15662598 :     if (ZV_isscalar(gx)) continue;
    2522    15786161 :     if (++try_factor > max_FACT) break;
    2523             : 
    2524    15622085 :     if (DEBUGLEVEL && Nsmall) (*Nsmall)++;
    2525    15622085 :     if (!factorgen(F,nf,I,NI,gx,fact)) continue;
    2526     2413444 :     if (!Nrelid) return 1;
    2527     2313735 :     if (jid == jid0)
    2528       28724 :       add_to_fact(jid, 1 + e0, fact);
    2529             :     else
    2530             :     {
    2531     2285011 :       add_to_fact(jid, 1, fact);
    2532     2285238 :       if (jid0) add_to_fact(jid0, e0, fact);
    2533             :     }
    2534             : 
    2535             :     /* smooth element */
    2536     2313962 :     R = set_fact(F, fact, rex, &nz);
    2537     2313973 :     cgx = Z_content(gx);
    2538     2313934 :     if (cgx)
    2539             :     { /* relatively rare, compute relation attached to gx/cgx */
    2540      502269 :       long i, n = fact[0].pr;
    2541      502269 :       gx = Q_div_to_int(gx, cgx);
    2542     2504689 :       for (i = 1; i <= n; i++) fact_update(R, F, fact[i].pr, cgx);
    2543      502276 :       if (rex)
    2544             :       {
    2545       32891 :         long l = lg(rex);
    2546      108205 :         for (i = 1; i < l; i++)
    2547       75314 :           if (rex[i])
    2548             :           {
    2549       73300 :             long t, ipr = F->subFB[i];
    2550      235280 :             for (t = 1; t <= n; t++)
    2551      185596 :               if (fact[t].pr == ipr) break;
    2552       73300 :             if (t > n) fact_update(R, F, ipr, cgx);
    2553             :           }
    2554             :       }
    2555             :     }
    2556     2313941 :     if (DEBUGLEVEL && Nfact) (*Nfact)++;
    2557     2313941 :     if (cache)
    2558             :     {
    2559             :       /* make sure we get maximal rank first, then allow all relations */
    2560     2313941 :       if (add_rel(cache, F, R, nz, gx, rex? 1: 0) <= 0)
    2561             :       { /* probably Q-dependent from previous ones: forget it */
    2562     1783030 :         if (DEBUGLEVEL>1) err_printf("*");
    2563     1783030 :         continue;
    2564             :       }
    2565      530966 :       if (cache->last >= cache->end) return 1; /* we have enough */
    2566             :     } else
    2567             :     {
    2568           0 :       gel(V,rel++) = gerepilecopy(av, mkvec3(R, stoi(nz), gx));
    2569           8 :       av = avma;
    2570             :     }
    2571      431279 :     if (++relid == Nrelid) break;
    2572             :   }
    2573      166869 :   END_Fincke_Pohst_ideal:
    2574      166869 :   return 0;
    2575             : }
    2576             : 
    2577             : static long
    2578      266572 : Fincke_Pohst_ideal(RELCACHE_t *cache, FB_t *F, GEN nf, GEN I, GEN NI,
    2579             :   FACT *fact, long Nrelid, long max_FACT, FP_t *fp, GEN rex, long jid, long jid0, long e0,
    2580             :   long *Nsmall, long *Nfact)
    2581             : {
    2582      266572 :   return Fincke_Pohst_ideal_both(cache, NULL,
    2583             :     F, nf, I, NI, fact, max_FACT, Nrelid, fp, rex, jid, jid0, e0, Nsmall, Nfact);
    2584             : }
    2585             : 
    2586             : static long
    2587           0 : Fincke_Pohst_ideal_par(GEN V, FB_t *F, GEN nf, GEN I, GEN NI,
    2588             :   FACT *fact, long max_FACT, FP_t *fp, GEN rex, long jid, long jid0, long e0,
    2589             :   long *Nsmall, long *Nfact)
    2590             : {
    2591           0 :   return Fincke_Pohst_ideal_both(NULL, V,
    2592             :     F, nf, I, NI, fact, max_FACT, max_FACT, fp, rex, jid, jid0, e0, Nsmall, Nfact);
    2593             : }
    2594             : 
    2595             : static GEN
    2596           0 : pack_FB(FB_t *F, long s)
    2597             : {
    2598           0 :   return mkvecn(s ? 8: 7, F->FB, F->LP, F->LV, F->iLP, F->idealperm, F->prodZ,
    2599             :            mkvecsmall3(F->KC,F->KCZ,F->KCZ2), F->subFB);
    2600             : }
    2601             : 
    2602             : static void
    2603           0 : unpack_FB(FB_t *F, GEN P)
    2604             : {
    2605           0 :   F->FB = gel(P,1);
    2606           0 :   F->LP = gel(P,2);
    2607           0 :   F->LV = gel(P,3);
    2608           0 :   F->iLP = gel(P,4);
    2609           0 :   F->idealperm = gel(P,5);
    2610           0 :   F->prodZ = gel(P,6);
    2611           0 :   F->KC = mael(P,7,1);
    2612           0 :   F->KCZ = mael(P,7,2);
    2613           0 :   F->KCZ2 = mael(P,7,3);
    2614           0 :   if (lg(P) > 8)
    2615           0 :     F->subFB = gel(P,8);
    2616           0 : }
    2617             : 
    2618             : GEN
    2619           0 : bnfinit_FP_worker(GEN INI, GEN PF, GEN nf, long max_FACT, GEN rex, long jid0, long e0)
    2620             : {
    2621           0 :   pari_sp av = avma;
    2622             :   FB_t F;
    2623             :   FP_t fp;
    2624             :   FACT * fact;
    2625           0 :   long Nsmall = 0, Nfact = 0, res, N = nf_get_degree(nf), jid = itos(gel(INI,3));
    2626           0 :   GEN vec = zerovec(max_FACT);
    2627           0 :   GEN I = gel(INI,1), NI = gel(INI,2);
    2628           0 :   if (isintzero(rex)) rex = NULL;
    2629           0 :   unpack_FB(&F, PF);
    2630           0 :   F.ballvol = ballvol(N);
    2631           0 :   minim_alloc(N+1, &fp.q, &fp.x, &fp.y, &fp.z, &fp.v);
    2632           0 :   fact = (FACT*)stack_malloc((F.KC+1)*sizeof(FACT));
    2633           0 :   res = Fincke_Pohst_ideal_par(vec, &F, nf, I, NI, fact, max_FACT, &fp, rex, jid, jid0, e0, &Nsmall, &Nfact);
    2634           0 :   return gerepilecopy(av, mkvec2(vec, mkvecsmall3(res, Nsmall, Nfact)));
    2635             : }
    2636             : 
    2637             : static void
    2638           0 : small_norm_par(RELCACHE_t *cache, FB_t *F, GEN nf, long max_FACT, long idex, long nbthr, long j0)
    2639             : {
    2640           0 :   GEN L_jid = F->L_jid, Np0 = NULL, p0 = j0? gel(F->LP,j0): NULL;
    2641           0 :   long Nsmall, Nfact, n = lg(L_jid)-1, e0 = 0;
    2642             :   pari_timer T;
    2643           0 :   long nt = nbthr? nbthr: mt_nbthreads();
    2644           0 :   GEN worker, vec = cgetg(nt+1, t_VEC);
    2645             : 
    2646           0 :   if (DEBUGLEVEL)
    2647             :   {
    2648           0 :     timer_start(&T);
    2649           0 :     err_printf("#### Look for %ld relations in %ld ideals (small_norm)\n",
    2650           0 :                cache->end - cache->last, lg(L_jid)-1);
    2651           0 :     if (p0) err_printf("Look in p0 = %Ps\n", vecslice(p0,1,4));
    2652             :   }
    2653           0 :   Nsmall = Nfact = 0;
    2654           0 :   if (p0)
    2655             :   {
    2656           0 :     GEN N0 = pr_norm(p0);
    2657           0 :     e0 = idex ? idex: logint0(sqri(pr_norm(veclast(F->LP))), N0, NULL);
    2658           0 :     p0 = idealpows(nf, p0, e0);
    2659           0 :     Np0 = powiu(N0, e0);
    2660             :   }
    2661           0 :   worker = snm_closure(is_entry("_bnfinit_FP_worker"),
    2662             :            mkcol6(pack_FB(F,0), nf, stoi(max_FACT), gen_0, stoi(j0), stoi(e0)));
    2663           0 :   while(n)
    2664             :   {
    2665             :     GEN VB;
    2666           0 :     long k, m = minss(n, nt);
    2667           0 :     for (k = 1; k <= m; k++, n--)
    2668             :     {
    2669           0 :       long j = L_jid[n];
    2670           0 :       GEN id = gel(F->LP,j), Nid;
    2671           0 :       if (p0)
    2672           0 :       { Nid = mulii(Np0, pr_norm(id)); id = idealmul(nf, p0, id); }
    2673             :       else
    2674           0 :       { Nid = pr_norm(id); id = pr_hnf(nf, id); }
    2675           0 :       gel(vec,k) = mkvec3(id, Nid, stoi(j));
    2676             :     }
    2677           0 :     setlg(vec,k);
    2678           0 :     VB = gen_parapply(worker,vec);
    2679           0 :     for (k = 1; k <= m; k++)
    2680             :     {
    2681           0 :       GEN B = gel(VB,k), B1 = gel(B,1), B2 = gel(B,2);
    2682           0 :       long i, lB = lg(B1);
    2683           0 :       Nsmall += B2[2]; Nfact += B2[3];
    2684           0 :       for (i = 1; i<lB && !isintzero(gel(B1,i)); i++)
    2685             :       {
    2686           0 :         GEN Bi = gel(B1,i), R = gel(Bi,1), gx = gel(Bi,3);
    2687           0 :         long nz = itos(gel(Bi,2));
    2688           0 :         if (cache->last < cache->end)
    2689           0 :           add_rel(cache, F, R, nz, gx, 0);
    2690             :       }
    2691           0 :       if (cache->last >= cache->end) { n = 0; break; }
    2692             :     }
    2693             :   }
    2694           0 :   if (DEBUGLEVEL && Nsmall)
    2695             :   {
    2696           0 :     if (DEBUGLEVEL == 1)
    2697           0 :     { if (Nfact) err_printf("\n"); }
    2698             :     else
    2699           0 :       err_printf("  \nnb. fact./nb. small norm = %ld/%ld = %.3f\n",
    2700           0 :                   Nfact,Nsmall,((double)Nfact)/Nsmall);
    2701           0 :     if (timer_get(&T)>1) timer_printf(&T,"small_norm");
    2702             :   }
    2703           0 : }
    2704             : 
    2705             : static void
    2706       66762 : small_norm_seq(RELCACHE_t *cache, FB_t *F, GEN nf, long Nrelid, long max_fact, long idex, FACT *fact, long j0)
    2707             : {
    2708       66762 :   const long N = nf_get_degree(nf);
    2709             :   FP_t fp;
    2710             :   pari_sp av;
    2711       66762 :   GEN L_jid = F->L_jid, Np0 = NULL, p0 = j0? gel(F->LP,j0): NULL;
    2712       66762 :   long Nsmall, Nfact, n = lg(L_jid), e0 = 0;
    2713             :   pari_timer T;
    2714             : 
    2715       66762 :   if (DEBUGLEVEL)
    2716             :   {
    2717           0 :     timer_start(&T);
    2718           0 :     err_printf("#### Look for %ld relations in %ld ideals (small_norm)\n",
    2719           0 :                cache->end - cache->last, lg(L_jid)-1);
    2720           0 :     if (p0) err_printf("Look in p0 = %Ps\n", vecslice(p0,1,4));
    2721             :   }
    2722       66762 :   Nsmall = Nfact = 0;
    2723       66762 :   minim_alloc(N+1, &fp.q, &fp.x, &fp.y, &fp.z, &fp.v);
    2724       66762 :   if (p0)
    2725             :   {
    2726       26701 :     GEN n = pr_norm(p0);
    2727       26701 :     e0 = idex ? idex: logint0(sqri(pr_norm(veclast(F->LP))), n, NULL);
    2728       26701 :     p0 = idealpows(nf, p0, e0);
    2729       26701 :     Np0 = powiu(n,e0);
    2730             :   }
    2731      165088 :   for (av = avma; --n; set_avma(av))
    2732             :   {
    2733      164670 :     long j = L_jid[n];
    2734      164670 :     GEN id = gel(F->LP, j), Nid;
    2735      164670 :     if (DEBUGLEVEL>1)
    2736           0 :       err_printf("\n*** Ideal no %ld: %Ps\n", j, vecslice(id,1,4));
    2737      164670 :     if (p0)
    2738             :     {
    2739       32492 :       if (j == j0)
    2740             :       { /* avoid trivial relation */
    2741        3894 :         long e = pr_get_e(id);
    2742        3894 :         if ((e0 + 1) % e == 0 && e * pr_get_f(id) == N) continue;
    2743             :       }
    2744       31849 :       Nid = mulii(Np0, pr_norm(id)); id = idealmul(nf, p0, id);
    2745             :     }
    2746             :     else
    2747      132178 :     { Nid = pr_norm(id); id = pr_hnf(nf, id);}
    2748      164028 :     if (Fincke_Pohst_ideal(cache, F, nf, id, Nid, fact, Nrelid, max_fact, &fp,
    2749       66346 :                            NULL, j, j0, e0, &Nsmall, &Nfact)) break;
    2750             :   }
    2751       66764 :   if (DEBUGLEVEL && Nsmall)
    2752             :   {
    2753           0 :     if (DEBUGLEVEL == 1)
    2754           0 :     { if (Nfact) err_printf("\n"); }
    2755             :     else
    2756           0 :       err_printf("  \nnb. fact./nb. small norm = %ld/%ld = %.3f\n",
    2757           0 :                   Nfact,Nsmall,((double)Nfact)/Nsmall);
    2758           0 :     if (timer_get(&T)>1) timer_printf(&T,"small_norm");
    2759             :   }
    2760       66764 : }
    2761             : 
    2762             : static void
    2763       66762 : small_norm(RELCACHE_t *cache, FB_t *F, GEN nf, long Nrelid, long max_fact, long idex, long nbthr, FACT *fact, long j0)
    2764             : {
    2765       66762 :   if (nbthr==1)
    2766       66762 :     return small_norm_seq(cache, F, nf, Nrelid, max_fact, idex, fact, j0);
    2767             :   else
    2768           0 :     return small_norm_par(cache, F, nf, max_fact, idex, nbthr, j0);
    2769             : }
    2770             : 
    2771             : static GEN
    2772       55612 : get_random_ideal(FB_t *F, GEN nf, GEN ex)
    2773             : {
    2774       55612 :   long i, l = lg(ex);
    2775             :   for (;;)
    2776        1033 :   {
    2777       56645 :     GEN I = NULL;
    2778      158690 :     for (i = 1; i < l; i++)
    2779      102046 :       if ((ex[i] = random_bits(RANDOM_BITS)))
    2780             :       {
    2781       97766 :         GEN pr = gel(F->LP, F->subFB[i]), e = utoipos(ex[i]);
    2782       97764 :         I = I? idealmulpowprime(nf, I, pr, e): idealpow(nf, pr, e);
    2783             :       }
    2784       56644 :     if (I && !ZM_isscalar(I,NULL)) return I; /* != (n)Z_K */
    2785             :   }
    2786             : }
    2787             : 
    2788             : static void
    2789           0 : rnd_rel_par(RELCACHE_t *cache, FB_t *F, GEN nf, long max_FACT)
    2790             : {
    2791             :   pari_timer T;
    2792           0 :   GEN L_jid = F->L_jid, R, ex;
    2793           0 :   long k, l = lg(L_jid), Nfact = 0, Nsmall = 0;
    2794             :   GEN worker, vec, VB, NR;
    2795             : 
    2796           0 :   if (DEBUGLEVEL) {
    2797           0 :     timer_start(&T);
    2798           0 :     err_printf("#### Look for %ld relations in %ld ideals (rnd_rel)\n",
    2799           0 :                cache->end - cache->last, l-1);
    2800             :   }
    2801           0 :   ex = cgetg(lg(F->subFB), t_VECSMALL);
    2802           0 :   R = get_random_ideal(F, nf, ex); /* random product from subFB */
    2803           0 :   NR = ZM_det_triangular(R);
    2804           0 :   worker = snm_closure(is_entry("_bnfinit_FP_worker"),
    2805             :            mkcol6(pack_FB(F,1), nf, stoi(max_FACT), ex, gen_0, gen_0));
    2806           0 :   vec = cgetg(l, t_VEC);
    2807           0 :   for (k = 1; k < l; k++)
    2808             :   {
    2809           0 :     long j = L_jid[k];
    2810           0 :     GEN id = gel(F->LP,j), Nid;
    2811           0 :     Nid = mulii(NR, pr_norm(id)); id = idealmul(nf, R, id);
    2812           0 :     gel(vec,k) = mkvec3(id, Nid, stoi(j));
    2813             :   }
    2814           0 :   VB = gen_parapply(worker,vec);
    2815           0 :   for (k = 1; k < l; k++)
    2816             :   {
    2817           0 :     GEN B = gel(VB,k), B1 = gel(B,1), B2 = gel(B,2);
    2818           0 :     long i, lB = lg(B1);
    2819           0 :     Nsmall += B2[2]; Nfact += B2[3];
    2820           0 :     for (i = 1; i<lB && !isintzero(gel(B1,i)); i++)
    2821             :     {
    2822           0 :       GEN Bi = gel(B1,i), R = gel(Bi,1), gx = gel(Bi,3);
    2823           0 :       long nz = itos(gel(Bi,2));
    2824           0 :       if (cache->last < cache->end)
    2825           0 :         add_rel(cache, F, R, nz, gx, 1);
    2826             :     }
    2827           0 :     if (cache->last >= cache->end) break;
    2828             :   }
    2829             : 
    2830           0 :   if (DEBUGLEVEL)
    2831             :   {
    2832           0 :     if (DEBUGLEVEL == 1)
    2833           0 :     { if (Nfact) err_printf("\n"); }
    2834             :     else
    2835           0 :       err_printf("  \nnb. fact./nb. small norm = %ld/%ld = %.3f\n",
    2836           0 :                   Nfact,Nsmall,((double)Nfact)/Nsmall);
    2837           0 :     if (timer_get(&T)>=0) timer_printf(&T,"rnd_rel");
    2838             :   }
    2839           0 : }
    2840             : 
    2841             : static void
    2842       55612 : rnd_rel_seq(RELCACHE_t *cache, FB_t *F, GEN nf, long max_fact, FACT *fact)
    2843             : {
    2844             :   pari_timer T;
    2845       55612 :   GEN L_jid = F->L_jid, R, NR, ex;
    2846       55612 :   long i, l = lg(L_jid), Nfact = 0;
    2847             :   FP_t fp;
    2848             :   pari_sp av;
    2849             : 
    2850       55612 :   if (DEBUGLEVEL) {
    2851           0 :     timer_start(&T);
    2852           0 :     err_printf("#### Look for %ld relations in %ld ideals (rnd_rel)\n",
    2853           0 :                cache->end - cache->last, l-1);
    2854             :   }
    2855       55612 :   ex = cgetg(lg(F->subFB), t_VECSMALL);
    2856       55612 :   R = get_random_ideal(F, nf, ex); /* random product from subFB */
    2857       55611 :   NR = ZM_det_triangular(R);
    2858       55608 :   minim_alloc(nf_get_degree(nf)+1, &fp.q, &fp.x, &fp.y, &fp.z, &fp.v);
    2859      124797 :   for (av = avma, i = 1; i < l; i++, set_avma(av))
    2860             :   { /* try P[j] * base */
    2861      102533 :     long j = L_jid[i];
    2862      102533 :     GEN P = gel(F->LP, j), Nid = mulii(NR, pr_norm(P));
    2863      102520 :     if (DEBUGLEVEL>1) err_printf("\n*** Ideal %ld: %Ps\n", j, vecslice(P,1,4));
    2864      102520 :     if (Fincke_Pohst_ideal(cache, F, nf, idealHNF_mul(nf, R, P), Nid, fact,
    2865       33349 :           RND_REL_RELPID, max_fact, &fp, ex, j, 0, 0, NULL, &Nfact)) break;
    2866             :   }
    2867       55613 :   if (DEBUGLEVEL)
    2868             :   {
    2869           0 :     if (Nfact) err_printf("\n");
    2870           0 :     if (timer_get(&T)>=0) timer_printf(&T,"rnd_rel");
    2871             :   }
    2872       55613 : }
    2873             : static void
    2874       55612 : rnd_rel(RELCACHE_t *cache, FB_t *F, GEN nf, long max_fact, long nbthr, FACT *fact)
    2875             : {
    2876       55612 :   if (nbthr==1)
    2877       55612 :     return rnd_rel_seq(cache, F, nf, max_fact, fact);
    2878             :   else
    2879           0 :     return rnd_rel_par(cache, F, nf, max_fact);
    2880             : }
    2881             : 
    2882             : static GEN
    2883       64000 : automorphism_perms(GEN M, GEN auts, GEN cyclic, long r1, long r2, long N)
    2884             : {
    2885       64000 :   long L = lgcols(M), lauts = lg(auts), lcyc = lg(cyclic), i, j, l, m;
    2886       64000 :   GEN Mt, perms = cgetg(lauts, t_VEC);
    2887             :   pari_sp av;
    2888             : 
    2889      128833 :   for (l = 1; l < lauts; l++) gel(perms, l) = cgetg(L, t_VECSMALL);
    2890       64000 :   av = avma;
    2891       64000 :   Mt = shallowtrans(gprec_w(M, LOWDEFAULTPREC));
    2892       64000 :   Mt = shallowconcat(Mt, conj_i(vecslice(Mt, r1+1, r1+r2)));
    2893      111450 :   for (l = 1; l < lcyc; l++)
    2894             :   {
    2895       47450 :     GEN thiscyc = gel(cyclic, l), thisperm, perm, prev, Nt;
    2896       47450 :     long k = thiscyc[1];
    2897             : 
    2898       47450 :     Nt = RgM_mul(shallowtrans(gel(auts, k)), Mt);
    2899       47451 :     perm = gel(perms, k);
    2900      157262 :     for (i = 1; i < L; i++)
    2901             :     {
    2902      109810 :       GEN v = gel(Nt, i), minD;
    2903      109810 :       minD = gnorml2(gsub(v, gel(Mt, 1)));
    2904      109808 :       perm[i] = 1;
    2905      577162 :       for (j = 2; j <= N; j++)
    2906             :       {
    2907      467351 :         GEN D = gnorml2(gsub(v, gel(Mt, j)));
    2908      467352 :         if (gcmp(D, minD) < 0) { minD = D; perm[i] = j >= L ? r2-j : j; }
    2909             :       }
    2910             :     }
    2911       66065 :     for (prev = perm, m = 2; m < lg(thiscyc); m++, prev = thisperm)
    2912             :     {
    2913       18613 :       thisperm = gel(perms, thiscyc[m]);
    2914       94360 :       for (i = 1; i < L; i++)
    2915             :       {
    2916       75747 :         long pp = labs(prev[i]);
    2917       75747 :         thisperm[i] = prev[i] < 0 ? -perm[pp] : perm[pp];
    2918             :       }
    2919             :     }
    2920             :   }
    2921       64000 :   set_avma(av); return perms;
    2922             : }
    2923             : 
    2924             : /* Determine the field automorphisms as matrices on the integral basis */
    2925             : static GEN
    2926       64061 : automorphism_matrices(GEN nf, GEN *cycp)
    2927             : {
    2928       64061 :   pari_sp av = avma;
    2929       64061 :   GEN auts = galoisconj(nf, NULL), mats, cyclic, cyclicidx;
    2930       64062 :   long nauts = lg(auts)-1, i, j, k, l;
    2931             : 
    2932       64062 :   cyclic = cgetg(nauts+1, t_VEC);
    2933       64062 :   cyclicidx = zero_Flv(nauts);
    2934       98478 :   for (l = 1; l <= nauts; l++)
    2935             :   {
    2936       98478 :     GEN aut = gel(auts, l);
    2937       98478 :     if (gequalX(aut)) { swap(gel(auts, l), gel(auts, nauts)); break; }
    2938             :   }
    2939             :   /* trivial automorphism is last */
    2940      192980 :   for (l = 1; l <= nauts; l++) gel(auts, l) = algtobasis(nf, gel(auts, l));
    2941             :   /* Compute maximal cyclic subgroups */
    2942      128920 :   for (l = nauts; --l > 0; ) if (!cyclicidx[l])
    2943             :   {
    2944       48956 :     GEN elt = gel(auts, l), aut = elt, cyc = cgetg(nauts+1, t_VECSMALL);
    2945       48956 :     cyc[1] = cyclicidx[l] = l; j = 1;
    2946             :     do
    2947             :     {
    2948       68112 :       elt = galoisapply(nf, elt, aut);
    2949      221626 :       for (k = 1; k <= nauts; k++) if (gequal(elt, gel(auts, k))) break;
    2950       68111 :       cyclicidx[k] = l; cyc[++j] = k;
    2951             :     }
    2952       68111 :     while (k != nauts);
    2953       48955 :     setlg(cyc, j);
    2954       48955 :     gel(cyclic, l) = cyc;
    2955             :   }
    2956      128919 :   for (i = j = 1; i < nauts; i++)
    2957       64859 :     if (cyclicidx[i] == i) cyclic[j++] = cyclic[i];
    2958       64060 :   setlg(cyclic, j);
    2959       64061 :   mats = cgetg(nauts, t_VEC);
    2960      111541 :   while (--j > 0)
    2961             :   {
    2962       47478 :     GEN cyc = gel(cyclic, j);
    2963       47478 :     long id = cyc[1];
    2964       47478 :     GEN M, Mi, aut = gel(auts, id);
    2965             : 
    2966       47478 :     gel(mats, id) = Mi = M = nfgaloismatrix(nf, aut);
    2967       66093 :     for (i = 2; i < lg(cyc); i++) gel(mats, cyc[i]) = Mi = ZM_mul(Mi, M);
    2968             :   }
    2969       64063 :   (void)gc_all(av, 2, &mats, &cyclic);
    2970       64063 :   if (cycp) *cycp = cyclic;
    2971       64063 :   return mats;
    2972             : }
    2973             : 
    2974             : /* vP a list of maximal ideals above the same p from idealprimedec: f(P/p) is
    2975             :  * increasing; 1 <= j <= #vP; orbit a zc of length <= #vP; auts a vector of
    2976             :  * automorphisms in ZM form.
    2977             :  * Set orbit[i] = 1 for all vP[i], i >= j, in the orbit of pr = vP[j] wrt auts.
    2978             :  * N.B.1 orbit need not be initialized to 0: useful to incrementally run
    2979             :  * through successive orbits
    2980             :  * N.B.2 i >= j, so primes with index < j will be missed; run incrementally
    2981             :  * starting from j = 1 ! */
    2982             : static void
    2983       11865 : pr_orbit_fill(GEN orbit, GEN auts, GEN vP, long j)
    2984             : {
    2985       11865 :   GEN pr = gel(vP,j), gen = pr_get_gen(pr);
    2986       11865 :   long i, l = lg(auts), J = lg(orbit), f = pr_get_f(pr);
    2987       11865 :   orbit[j] = 1;
    2988       23730 :   for (i = 1; i < l; i++)
    2989             :   {
    2990       11865 :     GEN g = ZM_ZC_mul(gel(auts,i), gen);
    2991             :     long k;
    2992       11886 :     for (k = j+1; k < J; k++)
    2993             :     {
    2994          35 :       GEN prk = gel(vP,k);
    2995          35 :       if (pr_get_f(prk) > f) break; /* f(P[k]) increases with k */
    2996             :       /* don't check that e matches: (almost) always 1 ! */
    2997          35 :       if (!orbit[k] && ZC_prdvd(g, prk)) { orbit[k] = 1; break; }
    2998             :     }
    2999             :   }
    3000       11865 : }
    3001             : /* remark: F->KCZ changes if be_honest() fails */
    3002             : static int
    3003           7 : be_honest(FB_t *F, GEN nf, GEN auts, FACT *fact)
    3004             : {
    3005             :   long i, iz, nbtest;
    3006           7 :   long lgsub = lg(F->subFB), KCZ0 = F->KCZ, N = nf_get_degree(nf);
    3007             :   FP_t fp;
    3008             :   pari_sp av;
    3009             : 
    3010           7 :   if (DEBUGLEVEL) {
    3011           0 :     err_printf("Be honest for %ld primes from %ld to %ld\n", F->KCZ2 - F->KCZ,
    3012           0 :                F->FB[ F->KCZ+1 ], F->FB[ F->KCZ2 ]);
    3013             :   }
    3014           7 :   minim_alloc(N+1, &fp.q, &fp.x, &fp.y, &fp.z, &fp.v);
    3015           7 :   if (lg(auts) == 1) auts = NULL;
    3016           7 :   av = avma;
    3017          14 :   for (iz=F->KCZ+1; iz<=F->KCZ2; iz++, set_avma(av))
    3018             :   {
    3019           7 :     long p = F->FB[iz];
    3020           7 :     GEN pr_orbit, P = gel(F->LV,p);
    3021           7 :     long j, J = lg(P); /* > 1 */
    3022             :     /* the P|p, NP > C2 are assumed in subgroup generated by FB + last P
    3023             :      * with NP <= C2 is unramified --> check all but last */
    3024           7 :     if (pr_get_e(gel(P,J-1)) == 1) J--;
    3025           7 :     if (J == 1) continue;
    3026           7 :     if (DEBUGLEVEL>1) err_printf("%ld ", p);
    3027           7 :     pr_orbit = auts? zero_zv(J-1): NULL;
    3028          28 :     for (j = 1; j < J; j++)
    3029             :     {
    3030             :       GEN Nid, id, id0;
    3031          21 :       if (pr_orbit)
    3032             :       {
    3033          21 :         if (pr_orbit[j]) continue;
    3034             :         /* discard all primes in automorphism orbit simultaneously */
    3035          14 :         pr_orbit_fill(pr_orbit, auts, P, j);
    3036             :       }
    3037          14 :       id = id0 = pr_hnf(nf,gel(P,j));
    3038          14 :       Nid = pr_norm(gel(P,j));
    3039          14 :       for (nbtest=0;;)
    3040             :       {
    3041          14 :         if (Fincke_Pohst_ideal(NULL, F, nf, id, Nid, fact, 0, MAXTRY_FACT, &fp,
    3042          14 :                                NULL, 0, 0, 0, NULL, NULL)) break;
    3043           0 :         if (++nbtest > maxtry_HONEST)
    3044             :         {
    3045           0 :           if (DEBUGLEVEL)
    3046           0 :             pari_warn(warner,"be_honest() failure on prime %Ps\n", gel(P,j));
    3047           0 :           return 0;
    3048             :         }
    3049             :         /* occurs at most once in the whole function */
    3050           0 :         for (i = 1, id = id0; i < lgsub; i++)
    3051             :         {
    3052           0 :           long ex = random_bits(RANDOM_BITS);
    3053           0 :           if (ex)
    3054             :           {
    3055           0 :             GEN pr = gel(F->LP, F->subFB[i]);
    3056           0 :             id = idealmulpowprime(nf, id, pr, utoipos(ex));
    3057             :           }
    3058             :         }
    3059           0 :         if (!equali1(gcoeff(id,N,N))) id = Q_primpart(id);
    3060           0 :         if (expi(gcoeff(id,1,1)) > 100) id = idealred(nf, id);
    3061           0 :         Nid = ZM_det_triangular(id);
    3062             :       }
    3063             :     }
    3064           7 :     F->KCZ++; /* SUCCESS, "enlarge" factorbase */
    3065             :   }
    3066           7 :   F->KCZ = KCZ0; return gc_bool(av,1);
    3067             : }
    3068             : 
    3069             : /* all primes with N(P) <= BOUND factor on factorbase ? */
    3070             : void
    3071          63 : bnftestprimes(GEN bnf, GEN BOUND)
    3072             : {
    3073          63 :   pari_sp av0 = avma, av;
    3074          63 :   ulong count = 0;
    3075          63 :   GEN auts, p, nf = bnf_get_nf(bnf), Vbase = bnf_get_vbase(bnf);
    3076          63 :   GEN fb = gen_sort_shallow(Vbase, (void*)&cmp_prime_ideal, cmp_nodata);
    3077          63 :   ulong pmax = pr_get_smallp(veclast(fb)); /*largest p in factorbase*/
    3078             :   forprime_t S;
    3079             :   FACT *fact;
    3080             :   FB_t F;
    3081             : 
    3082          63 :   (void)recover_partFB(&F, Vbase, nf_get_degree(nf));
    3083          63 :   fact = (FACT*)stack_malloc((F.KC+1)*sizeof(FACT));
    3084          63 :   forprime_init(&S, gen_2, BOUND);
    3085          63 :   auts = automorphism_matrices(nf, NULL);
    3086          63 :   if (lg(auts) == 1) auts = NULL;
    3087          63 :   av = avma;
    3088       37604 :   while (( p = forprime_next(&S) ))
    3089             :   {
    3090             :     GEN pr_orbit, vP;
    3091             :     long j, J;
    3092             : 
    3093       37541 :     if (DEBUGLEVEL == 1 && ++count > 1000)
    3094             :     {
    3095           0 :       err_printf("passing p = %Ps / %Ps\n", p, BOUND);
    3096           0 :       count = 0;
    3097             :     }
    3098       37541 :     set_avma(av);
    3099       37541 :     vP = idealprimedec_limit_norm(nf, p, BOUND);
    3100       37541 :     J = lg(vP);
    3101             :     /* if last is unramified, all P|p in subgroup generated by FB: skip last */
    3102       37541 :     if (J > 1 && pr_get_e(gel(vP,J-1)) == 1) J--;
    3103       37541 :     if (J == 1) continue;
    3104       14525 :     if (DEBUGLEVEL>1) err_printf("*** p = %Ps\n",p);
    3105       14525 :     pr_orbit = auts? zero_zv(J-1): NULL;
    3106       31549 :     for (j = 1; j < J; j++)
    3107             :     {
    3108       17024 :       GEN P = gel(vP,j);
    3109       17024 :       long k = 0;
    3110       17024 :       if (pr_orbit)
    3111             :       {
    3112       11858 :         if (pr_orbit[j]) continue;
    3113             :         /* discard all primes in automorphism orbit simultaneously */
    3114       11851 :         pr_orbit_fill(pr_orbit, auts, vP, j);
    3115             :       }
    3116       17017 :       if (abscmpiu(p, pmax) > 0 || !(k = tablesearch(fb, P, &cmp_prime_ideal)))
    3117       16408 :         (void)SPLIT(&F, nf, pr_hnf(nf,P), Vbase, fact);
    3118       17017 :       if (DEBUGLEVEL>1)
    3119             :       {
    3120           0 :         err_printf("  Testing P = %Ps\n",P);
    3121           0 :         if (k) err_printf("    #%ld in factor base\n",k);
    3122           0 :         else err_printf("    is %Ps\n", isprincipal(bnf,P));
    3123             :       }
    3124             :     }
    3125             :   }
    3126          63 :   set_avma(av0);
    3127          63 : }
    3128             : 
    3129             : /* A t_MAT of complex floats, in fact reals. Extract a submatrix B
    3130             :  * whose columns are definitely nonzero, i.e. gexpo(A[j]) >= -2
    3131             :  *
    3132             :  * If possible precision problem (t_REAL 0 with large exponent), set
    3133             :  * *precpb to 1 */
    3134             : static GEN
    3135       93032 : clean_cols(GEN A, int *precpb)
    3136             : {
    3137       93032 :   long l = lg(A), h, i, j, k;
    3138             :   GEN B;
    3139       93032 :   *precpb = 0;
    3140       93032 :   if (l == 1) return A;
    3141       93032 :   h = lgcols(A);;
    3142       93032 :   B = cgetg(l, t_MAT);
    3143     1092750 :   for (i = k = 1; i < l; i++)
    3144             :   {
    3145      999718 :     GEN Ai = gel(A,i);
    3146      999718 :     int non0 = 0;
    3147     4356649 :     for (j = 1; j < h; j++)
    3148             :     {
    3149     3356931 :       GEN c = gel(Ai,j);
    3150     3356931 :       if (gexpo(c) >= -2)
    3151             :       {
    3152     2017454 :         if (gequal0(c)) *precpb = 1; else non0 = 1;
    3153             :       }
    3154             :     }
    3155      999718 :     if (non0) gel(B, k++) = Ai;
    3156             :   }
    3157       93032 :   setlg(B, k); return B;
    3158             : }
    3159             : 
    3160             : static long
    3161      575962 : compute_multiple_of_R_pivot(GEN X, GEN x0/*unused*/, long ix, GEN c)
    3162             : {
    3163      575962 :   GEN x = gel(X,ix);
    3164      575962 :   long i, k = 0, ex = - (long)HIGHEXPOBIT, lx = lg(x);
    3165             :   (void)x0;
    3166     2836227 :   for (i=1; i<lx; i++)
    3167     2260280 :     if (!c[i] && !gequal0(gel(x,i)))
    3168             :     {
    3169      729598 :       long e = gexpo(gel(x,i));
    3170      729584 :       if (e > ex) { ex = e; k = i; }
    3171             :     }
    3172      575947 :   return (k && ex > -32)? k: lx;
    3173             : }
    3174             : 
    3175             : /* Ar = (log |sigma_i(u_j)|) for units (u_j) found so far;
    3176             :  * RU = R1+R2 = target rank for unit matrix, after adding [1 x r1, 2 x r2];
    3177             :  * N = field degree, need = unit rank defect;
    3178             :  * L = NULL (prec problem) or B^(-1) * A with approximate rational entries
    3179             :  * (as t_REAL), B a submatrix of A, with (probably) maximal rank RU */
    3180             : static GEN
    3181      121719 : compute_multiple_of_R(GEN Ar, long RU, long N, long *pneed, long *bit, GEN *ptL)
    3182             : {
    3183             :   GEN T, d, mdet, Im_mdet, kR, L;
    3184      121719 :   long i, j, r, R1 = 2*RU - N;
    3185             :   int precpb;
    3186      121719 :   pari_sp av = avma;
    3187             : 
    3188      121719 :   if (RU == 1) { *ptL = zeromat(0, lg(Ar)-1); return gen_1; }
    3189             : 
    3190       93032 :   if (DEBUGLEVEL) err_printf("\n#### Computing regulator multiple\n");
    3191       93032 :   mdet = clean_cols(Ar, &precpb);
    3192             :   /* will cause precision to increase on later failure, but we may succeed! */
    3193       93032 :   *ptL = precpb? NULL: gen_1;
    3194       93032 :   T = cgetg(RU+1,t_COL);
    3195      235149 :   for (i=1; i<=R1; i++) gel(T,i) = gen_1;
    3196      193194 :   for (   ; i<=RU; i++) gel(T,i) = gen_2;
    3197       93032 :   mdet = shallowconcat(T, mdet); /* det(Span(mdet)) = N * R */
    3198             : 
    3199             :   /* could be using indexrank(), but need custom "get_pivot" function */
    3200       93032 :   d = RgM_pivots(mdet, &r, &compute_multiple_of_R_pivot, NULL);
    3201             :   /* # of independent columns = target rank ? */
    3202       93032 :   if (lg(mdet)-1 - r != RU)
    3203             :   {
    3204       25361 :     if (DEBUGLEVEL)
    3205           0 :       err_printf("Units matrix target rank = %ld < %ld\n",lg(mdet)-1 - r, RU);
    3206       25361 :     *pneed = RU - (lg(mdet)-1-r); return gc_NULL(av);
    3207             :   }
    3208             : 
    3209       67671 :   Im_mdet = cgetg(RU+1, t_MAT); /* extract independent columns */
    3210             :   /* N.B: d[1] = 1, corresponding to T above */
    3211       67671 :   gel(Im_mdet, 1) = T;
    3212      257409 :   for (i = j = 2; i <= RU; j++)
    3213      189738 :     if (d[j]) gel(Im_mdet, i++) = gel(mdet,j);
    3214             : 
    3215             :   /* integral multiple of R: the cols we picked form a Q-basis, they have an
    3216             :    * index in the full lattice. First column is T */
    3217       67671 :   kR = divru(det2(Im_mdet), N);
    3218             :   /* R > 0.2 uniformly */
    3219       67671 :   if (!signe(kR) || expo(kR) < -3)
    3220             :   {
    3221           0 :     if (DEBUGLEVEL) err_printf("Regulator is zero.\n");
    3222           0 :     *pneed = 0; return gc_NULL(av);
    3223             :   }
    3224       67671 :   d = det2(rowslice(vecslice(Im_mdet, 2, RU), 2, RU));
    3225       67671 :   setabssign(d); setabssign(kR);
    3226       67671 :   if (gexpo(gsub(d,kR)) - gexpo(d) > -20) { *ptL = NULL; return gc_NULL(av); }
    3227       67670 :   L = RgM_inv(Im_mdet);
    3228             :   /* estimate # of correct bits in result */
    3229       67669 :   if (!L || (*bit = -gexpo(RgM_Rg_sub_shallow(RgM_mul(L,Im_mdet), gen_1))) < 16)
    3230          10 :   { *ptL = NULL; return gc_NULL(av); }
    3231             : 
    3232       67660 :   *ptL = RgM_mul(rowslice(L,2,RU), Ar); /* approximate rational entries */
    3233       67660 :   return gc_all(av,2, &kR, ptL);
    3234             : }
    3235             : 
    3236             : /* leave small integer n as is, convert huge n to t_REAL (for readability) */
    3237             : static GEN
    3238           0 : i2print(GEN n)
    3239           0 : { return lgefint(n) <= DEFAULTPREC? n: itor(n,LOWDEFAULTPREC); }
    3240             : 
    3241             : static long
    3242       96198 : bad_check(GEN c)
    3243             : {
    3244       96198 :   long ec = gexpo(c);
    3245       96198 :   if (DEBUGLEVEL) err_printf("\n ***** check = %.28Pg\n",c);
    3246             :   /* safe check for c < 0.75 : avoid underflow in gtodouble() */
    3247       96198 :   if (ec < -1 || (ec == -1 && gtodouble(c) < 0.75)) return fupb_PRECI;
    3248             :   /* safe check for c > 1.3 : avoid overflow */
    3249       96198 :   if (ec > 0 || (ec == 0 && gtodouble(c) > 1.3)) return fupb_RELAT;
    3250       64006 :   return fupb_NONE;
    3251             : }
    3252             : /* Input:
    3253             :  * lambda = approximate rational entries: coords of units found so far on a
    3254             :  * sublattice of maximal rank (sublambda)
    3255             :  * *ptkR = regulator of sublambda = multiple of regulator of lambda
    3256             :  * Compute R = true regulator of lambda.
    3257             :  *
    3258             :  * If c := Rz ~ 1, by Dirichlet's formula, then lambda is the full group of
    3259             :  * units AND the full set of relations for the class group has been computed.
    3260             :  * In fact z is a very rough approximation and we only expect 0.75 < Rz < 1.3
    3261             :  *
    3262             :  * Output: *ptkR = R, *ptL = numerator(units) (in terms of lambda) */
    3263             : static long
    3264       96260 : compute_R(GEN lambda, GEN z, GEN *ptL, GEN *ptkR)
    3265             : {
    3266       96260 :   pari_sp av = avma;
    3267       96260 :   long bit, r, reason, RU = lg(lambda) == 1? 1: lgcols(lambda);
    3268             :   GEN L, H, D, den, R, c;
    3269             : 
    3270       96261 :   *ptL = NULL;
    3271       96261 :   if (RU == 1) { *ptkR = gen_1; *ptL = lambda; return bad_check(z); }
    3272       67575 :   D = gmul2n(mpmul(*ptkR,z), 1); /* bound for denom(lambda) */
    3273       67576 :   if (expo(D) < 0 && rtodbl(D) < 0.95) return fupb_PRECI;
    3274       67576 :   L = bestappr(lambda,D);
    3275       67576 :   if (lg(L) == 1)
    3276             :   {
    3277           0 :     if (DEBUGLEVEL) err_printf("truncation error in bestappr\n");
    3278           0 :     return fupb_PRECI;
    3279             :   }
    3280       67576 :   den = Q_denom(L);
    3281       67576 :   if (mpcmp(den,D) > 0)
    3282             :   {
    3283          15 :     if (DEBUGLEVEL) err_printf("D = %Ps\nden = %Ps\n",D, i2print(den));
    3284          15 :     return fupb_PRECI;
    3285             :   }
    3286       67561 :   bit = -gexpo(gsub(L, lambda)); /* input accuracy */
    3287       67561 :   L = Q_muli_to_int(L, den);
    3288       67558 :   if (gexpo(L) + expi(den) > bit - 32)
    3289             :   {
    3290          47 :     if (DEBUGLEVEL) err_printf("dubious bestappr; den = %Ps\n", i2print(den));
    3291          47 :     return fupb_PRECI;
    3292             :   }
    3293       67512 :   H = ZM_hnf(L); r = lg(H)-1;
    3294       67513 :   if (!r || r != nbrows(H))
    3295           0 :     R = gen_0; /* wrong rank */
    3296             :   else
    3297       67513 :     R = gmul(*ptkR, gdiv(ZM_det_triangular(H), powiu(den, r)));
    3298             :   /* R = tentative regulator; regulator > 0.2 uniformly */
    3299       67513 :   if (gexpo(R) < -3) {
    3300           0 :     if (DEBUGLEVEL) err_printf("\n#### Tentative regulator: %.28Pg\n", R);
    3301           0 :     return gc_long(av, fupb_PRECI);
    3302             :   }
    3303       67513 :   c = gmul(R,z); /* should be n (= 1 if we are done) */
    3304       67513 :   if (DEBUGLEVEL) err_printf("\n#### Tentative regulator: %.28Pg\n", R);
    3305       67513 :   if ((reason = bad_check(c))) return gc_long(av, reason);
    3306       48796 :   *ptkR = R; *ptL = L; return fupb_NONE;
    3307             : }
    3308             : static GEN
    3309       64096 : get_clg2(GEN cyc, GEN Ga, GEN C, GEN Ur, GEN Ge, GEN M1, GEN M2)
    3310             : {
    3311       64096 :   GEN GD = gsub(act_arch(M1, C), diagact_arch(cyc, Ga));
    3312       64097 :   GEN ga = gsub(act_arch(M2, C), act_arch(Ur, Ga));
    3313       64098 :   return mkvecn(6, Ur, ga, GD, Ge, M1, M2);
    3314             : }
    3315             : /* compute class group (clg1) + data for isprincipal (clg2) */
    3316             : static GEN
    3317       64001 : class_group_gen(GEN nf,GEN W,GEN C,GEN Vbase,long prec, GEN *pclg2)
    3318             : {
    3319             :   GEN M1, M2, z, G, Ga, Ge, cyc, X, Y, D, U, V, Ur, Ui, Uir;
    3320             :   long j, l;
    3321             : 
    3322       64001 :   D = ZM_snfall(W,&U,&V); /* UWV=D, D diagonal, G = g Ui (G=new gens, g=old) */
    3323       64001 :   Ui = ZM_inv(U, NULL);
    3324       64001 :   l = lg(D); cyc = cgetg(l, t_VEC); /* elementary divisors */
    3325       92785 :   for (j = 1; j < l; j++)
    3326             :   {
    3327       30366 :     gel(cyc,j) = gcoeff(D,j,j); /* strip useless components */
    3328       30366 :     if (is_pm1(gel(cyc,j))) break;
    3329             :   }
    3330       64001 :   l = j;
    3331       64001 :   Ur  = ZM_hnfdivrem(U, D, &Y);
    3332       64001 :   Uir = ZM_hnfdivrem(Ui,W, &X);
    3333             :  /* {x} = logarithmic embedding of x (arch. component)
    3334             :   * NB: [J,z] = idealred(I) --> I = y J, with {y} = - z
    3335             :   * G = g Uir - {Ga},  Uir = Ui - WX
    3336             :   * g = G Ur  - {ga},  Ur  = U - DY */
    3337       64001 :   G = cgetg(l,t_VEC);
    3338       64001 :   Ga= cgetg(l,t_MAT);
    3339       64001 :   Ge= cgetg(l,t_COL);
    3340       64001 :   z = init_famat(NULL);
    3341       92784 :   for (j = 1; j < l; j++)
    3342             :   {
    3343       28784 :     GEN I = genback(z, nf, Vbase, gel(Uir,j));
    3344       28784 :     gel(G,j) = gel(I,1); /* generator, order cyc[j] */
    3345       28784 :     gel(Ge,j)= gel(I,2);
    3346       28784 :     gel(Ga,j)= nf_cxlog(nf, gel(I,2), prec);
    3347       28784 :     if (!gel(Ga,j)) pari_err_PREC("class_group_gen");
    3348             :   }
    3349             :   /* {ga} = - {GD}Y + G U - g = - {GD}Y - {Ga} U - gW X U
    3350             :                             = - gW (X Ur + V Y) - {Ga}Ur */
    3351       64000 :   M2 = ZM_neg(ZM_add(ZM_mul(X,Ur), ZM_mul(V,Y)));
    3352       64000 :   setlg(cyc,l); setlg(V,l); setlg(D,l);
    3353             :   /* G D =: {GD} = g (Ui - W X) D - {Ga}D = g W (V - X D) - {Ga}D
    3354             :    * NB: Ui D = W V. gW is given by (first l-1 cols of) C */
    3355       64000 :   M1 = ZM_sub(V, ZM_mul(X,D));
    3356       63999 :   *pclg2 = get_clg2(cyc, Ga, C, Ur, Ge, M1, M2);
    3357       64001 :   return mkvec3(ZV_prod(cyc), cyc, G);
    3358             : }
    3359             : 
    3360             : /* compute principal ideals corresponding to (gen[i]^cyc[i]) */
    3361             : static GEN
    3362        4956 : makecycgen(GEN bnf)
    3363             : {
    3364        4956 :   GEN cyc = bnf_get_cyc(bnf), gen = bnf_get_gen(bnf), nf = bnf_get_nf(bnf);
    3365        4956 :   GEN h, y, GD = bnf_get_GD(bnf), W = bnf_get_W(bnf); /* HNF */
    3366        4956 :   GEN SUnits = bnf_get_sunits(bnf);
    3367        4956 :   GEN X = SUnits? gel(SUnits,1): NULL, C = SUnits? gel(SUnits,3): NULL;
    3368             :   long e, i, l;
    3369             : 
    3370        4956 :   if (DEBUGLEVEL) pari_warn(warner,"completing bnf (building cycgen)");
    3371        4956 :   h = cgetg_copy(gen, &l);
    3372       11613 :   for (i = 1; i < l; i++)
    3373             :   {
    3374        6657 :     GEN gi = gel(gen,i), ci = gel(cyc,i);
    3375        6657 :     if (X && equalii(ci, gcoeff(W,i,i)))
    3376             :     {
    3377             :       long j;
    3378        8589 :       for (j = i+1; j < l; j++)
    3379        3213 :         if (signe(gcoeff(W,i,j))) break;
    3380        5550 :       if (j == i) { gel(h,i) = mkmat2(X, gel(C,i)); continue; }
    3381             :     }
    3382        6657 :     if (abscmpiu(ci, 5) < 0)
    3383             :     {
    3384        5544 :       GEN N = ZM_det_triangular(gi);
    3385        5544 :       y = isprincipalarch(bnf,gel(GD,i), N, ci, gen_1, &e);
    3386        5544 :       if (y && fact_ok(nf,y,NULL,mkvec(gi),mkvec(ci)))
    3387             :       {
    3388        4556 :         gel(h,i) = to_famat_shallow(y,gen_1);
    3389        4556 :         continue;
    3390             :       }
    3391             :     }
    3392        2101 :     y = isprincipalfact(bnf, NULL, mkvec(gi), mkvec(ci), nf_GENMAT|nf_FORCE);
    3393        2101 :     gel(h,i) = gel(y,2);
    3394             :   }
    3395        4956 :   return h;
    3396             : }
    3397             : 
    3398             : static GEN
    3399          69 : get_y(GEN bnf, GEN W, GEN B, GEN C, GEN pFB, long j)
    3400             : {
    3401          69 :   GEN y, nf  = bnf_get_nf(bnf);
    3402          69 :   long e, lW = lg(W)-1;
    3403          69 :   GEN ex = (j<=lW)? gel(W,j): gel(B,j-lW);
    3404          69 :   GEN P = (j<=lW)? NULL: gel(pFB,j);
    3405          69 :   if (C)
    3406             :   { /* archimedean embeddings known: cheap trial */
    3407          69 :     GEN Nx = get_norm_fact_primes(pFB, ex, P);
    3408          69 :     y = isprincipalarch(bnf,gel(C,j), Nx,gen_1, gen_1, &e);
    3409          69 :     if (y && fact_ok(nf,y,P,pFB,ex)) return y;
    3410             :   }
    3411           0 :   y = isprincipalfact_or_fail(bnf, P, pFB, ex);
    3412           0 :   return typ(y) == t_INT? y: gel(y,2);
    3413             : }
    3414             : /* compute principal ideals corresponding to bnf relations */
    3415             : static GEN
    3416          20 : makematal(GEN bnf)
    3417             : {
    3418          20 :   GEN W = bnf_get_W(bnf), B = bnf_get_B(bnf), C = bnf_get_C(bnf);
    3419             :   GEN pFB, ma, retry;
    3420          20 :   long lma, j, prec = 0;
    3421             : 
    3422          20 :   if (DEBUGLEVEL) pari_warn(warner,"completing bnf (building matal)");
    3423          20 :   lma=lg(W)+lg(B)-1;
    3424          20 :   pFB = bnf_get_vbase(bnf);
    3425          20 :   ma = cgetg(lma,t_VEC);
    3426          20 :   retry = vecsmalltrunc_init(lma);
    3427          89 :   for (j=lma-1; j>0; j--)
    3428             :   {
    3429          69 :     pari_sp av = avma;
    3430          69 :     GEN y = get_y(bnf, W, B, C, pFB, j);
    3431          69 :     if (typ(y) == t_INT)
    3432             :     {
    3433           0 :       long E = itos(y);
    3434           0 :       if (DEBUGLEVEL>1) err_printf("\n%ld done later at prec %ld\n",j,E);
    3435           0 :       set_avma(av);
    3436           0 :       vecsmalltrunc_append(retry, j);
    3437           0 :       if (E > prec) prec = E;
    3438             :     }
    3439             :     else
    3440             :     {
    3441          69 :       if (DEBUGLEVEL>1) err_printf("%ld ",j);
    3442          69 :       gel(ma,j) = gc_upto(av,y);
    3443             :     }
    3444             :   }
    3445          20 :   if (prec)
    3446             :   {
    3447           0 :     long k, l = lg(retry);
    3448           0 :     GEN y, nf = bnf_get_nf(bnf);
    3449           0 :     if (DEBUGLEVEL) pari_warn(warnprec,"makematal",prec);
    3450           0 :     nf = nfnewprec_shallow(nf,prec);
    3451           0 :     bnf = Buchall(nf, nf_FORCE, prec);
    3452           0 :     if (DEBUGLEVEL) err_printf("makematal, adding missing entries:");
    3453           0 :     for (k=1; k<l; k++)
    3454             :     {
    3455           0 :       pari_sp av = avma;
    3456           0 :       long j = retry[k];
    3457           0 :       y = get_y(bnf,W,B,NULL, pFB, j);
    3458           0 :       if (typ(y) == t_INT) pari_err_PREC("makematal");
    3459           0 :       if (DEBUGLEVEL>1) err_printf("%ld ",j);
    3460           0 :       gel(ma,j) = gc_upto(av,y);
    3461             :     }
    3462             :   }
    3463          20 :   if (DEBUGLEVEL>1) err_printf("\n");
    3464          20 :   return ma;
    3465             : }
    3466             : 
    3467             : enum { MATAL = 1, CYCGEN, UNITS };
    3468             : GEN
    3469       26726 : bnf_build_cycgen(GEN bnf)
    3470       26726 : { return obj_checkbuild(bnf, CYCGEN, &makecycgen); }
    3471             : GEN
    3472          20 : bnf_build_matalpha(GEN bnf)
    3473          20 : { return obj_checkbuild(bnf, MATAL, &makematal); }
    3474             : GEN
    3475       50738 : bnf_build_units(GEN bnf)
    3476       50738 : { return obj_checkbuild(bnf, UNITS, &makeunits); }
    3477             : 
    3478             : /* return fu in compact form if available; in terms of a fixed basis
    3479             :  * of S-units */
    3480             : GEN
    3481          70 : bnf_compactfu_mat(GEN bnf)
    3482             : {
    3483          70 :   GEN X, U, SUnits = bnf_get_sunits(bnf);
    3484          70 :   if (!SUnits) return NULL;
    3485          70 :   X = gel(SUnits,1);
    3486          70 :   U = gel(SUnits,2); ZM_remove_unused(&U, &X);
    3487          70 :   return mkvec2(X, U);
    3488             : }
    3489             : /* return fu in compact form if available; individually as famat */
    3490             : GEN
    3491       37415 : bnf_compactfu(GEN bnf)
    3492             : {
    3493       37415 :   GEN fu, X, U, SUnits = bnf_get_sunits(bnf);
    3494             :   long i, l;
    3495       37415 :   if (!SUnits) return NULL;
    3496       37177 :   X = gel(SUnits,1);
    3497       37177 :   U = gel(SUnits,2); l = lg(U); fu = cgetg(l, t_VEC);
    3498       61201 :   for (i = 1; i < l; i++)
    3499       24024 :     gel(fu,i) = famat_remove_trivial(mkmat2(X, gel(U,i)));
    3500       37177 :   return fu;
    3501             : }
    3502             : /* return expanded fu if available */
    3503             : GEN
    3504      285769 : bnf_has_fu(GEN bnf)
    3505             : {
    3506      285769 :   GEN fu = obj_check(bnf, UNITS);
    3507      285767 :   if (fu) return vecsplice(fu, 1);
    3508      264112 :   fu = bnf_get_fu_nocheck(bnf);
    3509      264111 :   return (typ(fu) == t_MAT)? NULL: fu;
    3510             : }
    3511             : /* return expanded fu if available; build if cheap */
    3512             : GEN
    3513      285482 : bnf_build_cheapfu(GEN bnf)
    3514             : {
    3515             :   GEN fu, SUnits;
    3516      285482 :   if ((fu = bnf_has_fu(bnf))) return fu;
    3517         142 :   if ((SUnits = bnf_get_sunits(bnf)))
    3518             :   {
    3519         142 :     pari_sp av = avma;
    3520         142 :     long e = gexpo(real_i(bnf_get_logfu(bnf)));
    3521         142 :     set_avma(av); if (e < 13) return vecsplice(bnf_build_units(bnf), 1);
    3522             :   }
    3523          77 :   return NULL;
    3524             : }
    3525             : 
    3526             : static GEN
    3527       48887 : get_regulator(GEN A)
    3528             : {
    3529       48887 :   pari_sp av = avma;
    3530             :   GEN R;
    3531             : 
    3532       48887 :   if (lg(A) == 1) return gen_1;
    3533       48880 :   R = det( rowslice(real_i(A), 1, lgcols(A)-2) );
    3534       48880 :   setabssign(R); return gc_leaf(av, R);
    3535             : }
    3536             : 
    3537             : /* return corrected archimedian components for elts of x (vector)
    3538             :  * (= log(sigma_i(x)) - log(|Nx|) / [K:Q]) */
    3539             : static GEN
    3540          40 : get_archclean(GEN nf, GEN x, long prec, int units)
    3541             : {
    3542          40 :   long k, N, l = lg(x);
    3543          40 :   GEN M = cgetg(l, t_MAT);
    3544             : 
    3545          40 :   if (l == 1) return M;
    3546          26 :   N = nf_get_degree(nf);
    3547         114 :   for (k = 1; k < l; k++)
    3548             :   {
    3549          88 :     pari_sp av = avma;
    3550          88 :     GEN c = nf_cxlog(nf, gel(x,k), prec);
    3551          88 :     if (!c || (!units && !(c = cleanarch(c, N, NULL,prec)))) return NULL;
    3552          88 :     gel(M,k) = gc_GEN(av, c);
    3553             :   }
    3554          26 :   return M;
    3555             : }
    3556             : static void
    3557          77 : SUnits_archclean(GEN nf, GEN SUnits, GEN *pmun, GEN *pC, long prec)
    3558             : {
    3559          77 :   GEN ipi, M, X = gel(SUnits,1), U = gel(SUnits,2), G = gel(SUnits,3);
    3560          77 :   long k, N = nf_get_degree(nf), l = lg(X);
    3561             : 
    3562          77 :   M = cgetg(l, t_MAT);
    3563        3640 :   for (k = 1; k < l; k++)
    3564        3563 :     if (!(gel(M,k) = nf_cxlog(nf, gel(X,k), prec))) return;
    3565          77 :   ipi = invr(mppi(prec));
    3566          77 :   *pmun = cleanarch(RgM_ZM_mul(M, U), N, ipi, prec); /* not cleanarchunit ! */
    3567          77 :   if (*pmun) *pC = cleanarch(RgM_ZM_mul(M, G), N, ipi, prec);
    3568             : }
    3569             : 
    3570             : GEN
    3571          97 : bnfnewprec_shallow(GEN bnf, long prec)
    3572             : {
    3573          97 :   GEN nf0 = bnf_get_nf(bnf), nf, v, fu, matal, y, A, C;
    3574          97 :   GEN SUnits = bnf_get_sunits(bnf), Ur, Ga, Ge, M1, M2;
    3575          97 :   long r1, r2, prec0 = prec;
    3576             : 
    3577          97 :   nf_get_sign(nf0, &r1, &r2);
    3578          97 :   if (SUnits)
    3579             :   {
    3580          77 :     fu = matal = NULL;
    3581          77 :     prec += nbits2extraprec(gexpo(SUnits));
    3582             :   }
    3583             :   else
    3584             :   {
    3585          20 :     fu = bnf_build_units(bnf);
    3586          20 :     fu = vecslice(fu, 2, lg(fu)-1);
    3587          20 :     if (r1 + r2 > 1) {
    3588          13 :       long e = gexpo(bnf_get_logfu(bnf)) + 1 - TWOPOTBITS_IN_LONG;
    3589          13 :       if (e >= 0) prec += nbits2extraprec(e);
    3590             :     }
    3591          20 :     matal = bnf_build_matalpha(bnf);
    3592             :   }
    3593             : 
    3594          97 :   if (DEBUGLEVEL && prec0 != prec) pari_warn(warnprec,"bnfnewprec",prec);
    3595          97 :   for(C = NULL;;)
    3596           0 :   {
    3597          97 :     pari_sp av = avma;
    3598          97 :     nf = nfnewprec_shallow(nf0,prec);
    3599          97 :     if (SUnits)
    3600          77 :       SUnits_archclean(nf, SUnits, &A, &C, prec);
    3601             :     else
    3602             :     {
    3603          20 :       A = get_archclean(nf, fu, prec, 1);
    3604          20 :       if (A) C = get_archclean(nf, matal, prec, 0);
    3605             :     }
    3606          97 :     if (C) break;
    3607           0 :     set_avma(av); prec = precdbl(prec);
    3608           0 :     if (DEBUGLEVEL) pari_warn(warnprec,"bnfnewprec(extra)",prec);
    3609             :   }
    3610          97 :   y = leafcopy(bnf);
    3611          97 :   gel(y,3) = A;
    3612          97 :   gel(y,4) = C;
    3613          97 :   gel(y,7) = nf;
    3614          97 :   gel(y,8) = v = leafcopy(gel(bnf,8));
    3615          97 :   gel(v,2) = get_regulator(A);
    3616          97 :   v = gel(bnf,9);
    3617          97 :   if (lg(v) < 7) pari_err_TYPE("bnfnewprec [obsolete bnf format]", bnf);
    3618          97 :   Ur = gel(v,1);
    3619          97 :   Ge = gel(v,4);
    3620          97 :   Ga = nfV_cxlog(nf, Ge, prec);
    3621          97 :   M1 = gel(v,5);
    3622          97 :   M2 = gel(v,6);
    3623          97 :   gel(y,9) = get_clg2(bnf_get_cyc(bnf), Ga, C, Ur, Ge, M1, M2);
    3624          97 :   return y;
    3625             : }
    3626             : GEN
    3627           7 : bnfnewprec(GEN bnf, long prec)
    3628             : {
    3629           7 :   pari_sp av = avma;
    3630           7 :   return gc_GEN(av, bnfnewprec_shallow(checkbnf(bnf), prec));
    3631             : }
    3632             : 
    3633             : GEN
    3634           0 : bnrnewprec_shallow(GEN bnr, long prec)
    3635             : {
    3636           0 :   GEN y = cgetg(7,t_VEC);
    3637             :   long i;
    3638           0 :   gel(y,1) = bnfnewprec_shallow(bnr_get_bnf(bnr), prec);
    3639           0 :   for (i=2; i<7; i++) gel(y,i) = gel(bnr,i);
    3640           0 :   return y;
    3641             : }
    3642             : GEN
    3643           7 : bnrnewprec(GEN bnr, long prec)
    3644             : {
    3645           7 :   GEN y = cgetg(7,t_VEC);
    3646             :   long i;
    3647           7 :   checkbnr(bnr);
    3648           7 :   gel(y,1) = bnfnewprec(bnr_get_bnf(bnr), prec);
    3649          42 :   for (i=2; i<7; i++) gel(y,i) = gcopy(gel(bnr,i));
    3650           7 :   return y;
    3651             : }
    3652             : 
    3653             : static GEN
    3654       65205 : buchall_end(GEN nf,GEN res, GEN clg2, GEN W, GEN B, GEN A, GEN C,GEN Vbase)
    3655             : {
    3656       65205 :   GEN z = obj_init(9, 3);
    3657       65205 :   gel(z,1) = W;
    3658       65205 :   gel(z,2) = B;
    3659       65205 :   gel(z,3) = A;
    3660       65205 :   gel(z,4) = C;
    3661       65205 :   gel(z,5) = Vbase;
    3662       65205 :   gel(z,6) = gen_0;
    3663       65205 :   gel(z,7) = nf;
    3664       65205 :   gel(z,8) = res;
    3665       65205 :   gel(z,9) = clg2;
    3666       65205 :   return z;
    3667             : }
    3668             : 
    3669             : GEN
    3670        2632 : bnfinit0(GEN P, long flag, GEN data, long prec)
    3671             : {
    3672        2632 :   double c1 = 0., c2 = 0.;
    3673        2632 :   long fl, relpid = BNF_RELPID, max_fact = MAXTRY_FACT, idex = 0, nbthr = 1, s;
    3674             : 
    3675        2632 :   if (data)
    3676             :   {
    3677          21 :     long lx = lg(data);
    3678          21 :     if (typ(data) != t_VEC || lx > 7) pari_err_TYPE("bnfinit",data);
    3679          21 :     switch(lx)
    3680             :     {
    3681           0 :       case 7: nbthr = itou(gel(data,6)); if (nbthr <= 1) nbthr = 1-nbthr;
    3682           0 :       case 6: idex = itou(gel(data,5));
    3683           0 :       case 5: s = itou(gel(data,4)); if (s) max_fact = s;
    3684           0 :       case 4: s = itos(gel(data,3)); if (s) relpid = s < 0 ? 0 : s;
    3685          14 :       case 3: c2 = gtodouble(gel(data,2));
    3686          21 :       case 2: c1 = gtodouble(gel(data,1));
    3687             :     }
    3688             :   }
    3689        2632 :   switch(flag)
    3690             :   {
    3691        1778 :     case 2:
    3692        1778 :     case 0: fl = 0; break;
    3693         854 :     case 1: fl = nf_FORCE; break;
    3694           0 :     default: pari_err_FLAG("bnfinit");
    3695             :       return NULL; /* LCOV_EXCL_LINE */
    3696             :   }
    3697        2632 :   return Buchall_param(P, c1, c2, relpid, max_fact, idex, nbthr, fl, prec);
    3698             : }
    3699             : GEN
    3700       62578 : Buchall(GEN P, long flag, long prec)
    3701       62578 : { return Buchall_param(P, 0., 0., BNF_RELPID, MAXTRY_FACT, 0, 1, flag & nf_FORCE, prec); }
    3702             : 
    3703             : static GEN
    3704        1204 : Buchall_deg1(GEN nf)
    3705             : {
    3706        1204 :   GEN v = cgetg(1,t_VEC), m = cgetg(1,t_MAT);
    3707        1204 :   GEN res, W, A, B, C, Vbase = cgetg(1,t_COL);
    3708        1204 :   GEN fu = v, R = gen_1, zu = mkvec2(gen_2, gen_m1);
    3709        1204 :   GEN clg1 = mkvec3(gen_1,v,v), clg2 = mkvecn(6, m,m,m,v,m,m);
    3710             : 
    3711        1204 :   W = A = B = C = m; res = mkvec5(clg1, R, gen_1, zu, fu);
    3712        1204 :   return buchall_end(nf,res,clg2,W,B,A,C,Vbase);
    3713             : }
    3714             : 
    3715             : /* return (small set of) indices of columns generating the same lattice as x.
    3716             :  * Assume HNF(x) is inexpensive (few rows, many columns).
    3717             :  * Dichotomy approach since interesting columns may be at the very end */
    3718             : GEN
    3719       64007 : extract_full_lattice(GEN x)
    3720             : {
    3721       64007 :   long dj, j, k, l = lg(x);
    3722             :   GEN h, h2, H, v;
    3723             : 
    3724       64007 :   if (l < 200) return NULL; /* not worth it */
    3725             : 
    3726           1 :   v = vecsmalltrunc_init(l);
    3727           1 :   H = ZM_hnf(x);
    3728           1 :   h = cgetg(1, t_MAT);
    3729           1 :   dj = 1;
    3730          43 :   for (j = 1; j < l; )
    3731             :   {
    3732          43 :     pari_sp av = avma;
    3733          43 :     long lv = lg(v);
    3734             : 
    3735         145 :     for (k = 0; k < dj; k++) v[lv+k] = j+k;
    3736          43 :     setlg(v, lv + dj);
    3737          43 :     h2 = ZM_hnf(vecpermute(x, v));
    3738          43 :     if (ZM_equal(h, h2))
    3739             :     { /* these dj columns can be eliminated */
    3740          17 :       set_avma(av); setlg(v, lv);
    3741          17 :       j += dj;
    3742          17 :       if (j >= l) break;
    3743          17 :       dj <<= 1;
    3744          17 :       if (j + dj >= l) { dj = (l - j) >> 1; if (!dj) dj = 1; }
    3745             :     }
    3746          26 :     else if (dj > 1)
    3747             :     { /* at least one interesting column, try with first half of this set */
    3748          17 :       set_avma(av); setlg(v, lv);
    3749          17 :       dj >>= 1; /* > 0 */
    3750             :     }
    3751             :     else
    3752             :     { /* this column should be kept */
    3753           9 :       if (ZM_equal(h2, H)) break;
    3754           8 :       h = h2; j++;
    3755             :     }
    3756             :   }
    3757           1 :   return v;
    3758             : }
    3759             : 
    3760             : static void
    3761       64073 : init_rel(RELCACHE_t *cache, FB_t *F, long add_need)
    3762             : {
    3763       64073 :   const long n = F->KC + add_need; /* expected # of needed relations */
    3764             :   long i, j, k, p;
    3765             :   GEN c, P;
    3766             :   GEN R;
    3767             : 
    3768       64073 :   if (DEBUGLEVEL) err_printf("KCZ = %ld, KC = %ld, n = %ld\n", F->KCZ,F->KC,n);
    3769       64073 :   reallocate(cache, 10*n + 50); /* make room for lots of relations */
    3770       64074 :   cache->chk = cache->base;
    3771       64074 :   cache->end = cache->base + n;
    3772       64074 :   cache->relsup = add_need;
    3773       64074 :   cache->last = cache->base;
    3774       64074 :   cache->missing = lg(cache->basis) - 1;
    3775      306267 :   for (i = 1; i <= F->KCZ; i++)
    3776             :   { /* trivial relations (p) = prod P^e */
    3777      242193 :     p = F->FB[i]; P = gel(F->LV,p);
    3778      242193 :     if (!isclone(P)) continue;
    3779             : 
    3780             :     /* all prime divisors in FB */
    3781      169012 :     c = zero_Flv(F->KC); k = F->iLP[p];
    3782      169010 :     R = c; c += k;
    3783      539697 :     for (j = lg(P)-1; j; j--) c[j] = pr_get_e(gel(P,j));
    3784      169009 :     add_rel(cache, F, R, k+1, pr_get_p(gel(P,1)), 0);
    3785             :   }
    3786       64074 : }
    3787             : 
    3788             : /* Let z = \zeta_n in nf. List of not-obviously-dependent generators for
    3789             :  * cyclotomic units modulo torsion in Q(z) [independent when n a prime power]:
    3790             :  * - z^a - 1,  n/(a,n) not a prime power, a \nmid n unless a=1,  1 <= a < n/2
    3791             :  * - (Z^a - 1)/(Z - 1),  p^k || n, Z = z^{n/p^k}, (p,a) = 1, 1 < a <= (p^k-1)/2
    3792             :  */
    3793             : GEN
    3794       64074 : nfcyclotomicunits(GEN nf, GEN zu)
    3795             : {
    3796       64074 :   long n = itos(gel(zu, 1)), n2, lP, i, a;
    3797             :   GEN z, fa, P, E, L, mz, powz;
    3798       64074 :   if (n <= 6) return cgetg(1, t_VEC);
    3799             : 
    3800        1911 :   z = algtobasis(nf,gel(zu, 2));
    3801        1911 :   if ((n & 3) == 2) { n = n >> 1; z = ZC_neg(z); } /* ensure n != 2 (mod 4) */
    3802        1911 :   n2 = n/2;
    3803        1911 :   mz = zk_multable(nf, z); /* multiplication by z */
    3804        1911 :   powz = cgetg(n2, t_VEC); gel(powz,1) = z;
    3805        6286 :   for (i = 2; i < n2; i++) gel(powz,i) = ZM_ZC_mul(mz, gel(powz,i-1));
    3806             :   /* powz[i] = z^i */
    3807             : 
    3808        1911 :   L = vectrunc_init(n);
    3809        1911 :   fa = factoru(n);
    3810        1911 :   P = gel(fa,1); lP = lg(P);
    3811        1911 :   E = gel(fa,2);
    3812        4613 :   for (i = 1; i < lP; i++)
    3813             :   { /* second kind */
    3814        2702 :     long p = P[i], k = E[i], pk = upowuu(p,k), pk2 = (pk-1) / 2;
    3815        2702 :     GEN u = gen_1;
    3816        4970 :     for (a = 2; a <= pk2; a++)
    3817             :     {
    3818        2268 :       u = nfadd(nf, u, gel(powz, (n/pk) * (a-1))); /* = (Z^a-1)/(Z-1) */
    3819        2268 :       if (a % p) vectrunc_append(L, u);
    3820             :     }
    3821             :   }
    3822        6160 :   if (lP > 2) for (a = 1; a < n2; a++)
    3823             :   { /* first kind, when n not a prime power */
    3824             :     ulong p;
    3825        4249 :     if (a > 1 && (n % a == 0 || uisprimepower(n/ugcd(a,n), &p))) continue;
    3826        1869 :     vectrunc_append(L, nfadd(nf, gel(powz, a), gen_m1));
    3827             :   }
    3828        1911 :   return L;
    3829             : }
    3830             : static void
    3831       64074 : add_cyclotomic_units(GEN nf, GEN zu, RELCACHE_t *cache, FB_t *F)
    3832             : {
    3833       64074 :   pari_sp av = avma;
    3834       64074 :   GEN L = nfcyclotomicunits(nf, zu);
    3835       64073 :   long i, l = lg(L);
    3836       64073 :   if (l > 1)
    3837             :   {
    3838        1911 :     GEN R = zero_Flv(F->KC);
    3839        5950 :     for(i = 1; i < l; i++) add_rel(cache, F, R, F->KC+1, gel(L,i), 0);
    3840             :   }
    3841       64073 :   set_avma(av);
    3842       64073 : }
    3843             : 
    3844             : static GEN
    3845      122448 : trim_list(FB_t *F)
    3846             : {
    3847      122448 :   pari_sp av = avma;
    3848      122448 :   GEN v, L_jid = F->L_jid, minidx = F->minidx, present = zero_Flv(F->KC);
    3849      122448 :   long i, j, imax = minss(lg(L_jid), F->KC + 1);
    3850             : 
    3851      122448 :   v = cgetg(imax, t_VECSMALL);
    3852     1332157 :   for (i = j = 1; i < imax; i++)
    3853             :   {
    3854     1209709 :     long k = minidx[ L_jid[i] ];
    3855     1209709 :     if (!present[k]) { v[j++] = L_jid[i]; present[k] = 1; }
    3856             :   }
    3857      122448 :   setlg(v, j); return gc_leaf(av, v);
    3858             : }
    3859             : 
    3860             : /* x t_INT or primitive ZC */
    3861             : static void
    3862        1649 : try_elt(RELCACHE_t *cache, FB_t *F, GEN nf, GEN x, FACT *fact)
    3863             : {
    3864        1649 :   pari_sp av = avma;
    3865             :   long nz;
    3866             :   GEN R;
    3867             : 
    3868        1649 :   if (typ(x) == t_INT /* 2nd path can't fail */
    3869        1649 :      || !can_factor(F, nf, NULL, x, nfnorm(nf, x), fact)) return;
    3870             :   /* smooth element */
    3871        1428 :   R = set_fact(F, fact, NULL, &nz);
    3872             :   /* make sure we get maximal rank first, then allow all relations */
    3873        1428 :   (void)add_rel(cache, F, R, nz, x, 0);
    3874        1428 :   set_avma(av);
    3875             : }
    3876             : 
    3877             : static void
    3878       55507 : matenlarge(GEN C, long h)
    3879             : {
    3880       55507 :   GEN _0 = zerocol(h);
    3881             :   long i;
    3882     1264920 :   for (i = lg(C); --i; ) gel(C,i) = shallowconcat(gel(C,i), _0);
    3883       55508 : }
    3884             : 
    3885             : /* E = floating point embeddings */
    3886             : static GEN
    3887       55507 : matbotidembs(RELCACHE_t *cache, GEN E)
    3888             : {
    3889       55507 :   long w = cache->last - cache->chk, h = cache->last - cache->base;
    3890       55507 :   long j, d = h - w, hE = nbrows(E);
    3891       55507 :   GEN y = cgetg(w+1,t_MAT), _0 = zerocol(h);
    3892      217579 :   for (j = 1; j <= w; j++)
    3893             :   {
    3894      162072 :     GEN c = shallowconcat(gel(E,j), _0);
    3895      162072 :     if (d + j >= 1) gel(c, d + j + hE) = gen_1;
    3896      162072 :     gel(y,j) = c;
    3897             :   }
    3898       55507 :   return y;
    3899             : }
    3900             : static GEN
    3901       62485 : matbotid(RELCACHE_t *cache)
    3902             : {
    3903       62485 :   long w = cache->last - cache->chk, h = cache->last - cache->base;
    3904       62485 :   long j, d = h - w;
    3905       62485 :   GEN y = cgetg(w+1,t_MAT);
    3906      851548 :   for (j = 1; j <= w; j++)
    3907             :   {
    3908      789064 :     GEN c = zerocol(h);
    3909      789063 :     if (d + j >= 1) gel(c, d + j) = gen_1;
    3910      789063 :     gel(y,j) = c;
    3911             :   }
    3912       62484 :   return y;
    3913             : }
    3914             : 
    3915             : static long
    3916          73 : myprecdbl(long prec, GEN C)
    3917             : {
    3918          73 :   long p = prec < 1280? precdbl(prec): (long)(prec * 1.5);
    3919          73 :   if (C) p = maxss(p, minss(3*p, prec + nbits2extraprec(gexpo(C))));
    3920          73 :   return p;
    3921             : }
    3922             : 
    3923             : static GEN
    3924       57721 : _nfnewprec(GEN nf, long prec, long *isclone)
    3925             : {
    3926       57721 :   GEN NF = gclone(nfnewprec_shallow(nf, prec));
    3927       57721 :   if (*isclone) gunclone(nf);
    3928       57721 :   *isclone = 1; return NF;
    3929             : }
    3930             : 
    3931             : /* In small_norm, LLL reduction produces v0 in I such that
    3932             : *     T2(v0) <= (4/3)^((n-1)/2) (NI sqrt(disc(K)))^(2/n)
    3933             : * NI <= LIMCMAX^2. We consider v with T2(v) ~ T2(v0), hence
    3934             : *     Nv <= ((4/3)^((n-1)/2) / n)^(n/2) LIMCMAX^2 sqrt(disc(K)) */
    3935             : static long
    3936       63993 : small_norm_prec(long N, double LOGD, long LIMCMAX)
    3937             : {
    3938       63993 :   double a = N/2. * ((N-1)/2.*log(4./3) - log((double)N));
    3939       63993 :   double b = 2*log((double)LIMCMAX) + LOGD/2;
    3940       63993 :   return nbits2prec(BITS_IN_LONG + (a + b) / M_LN2);
    3941             : }
    3942             : 
    3943             : /* Nrelid = nb relations per ideal, possibly 0. If flag is set, keep data in
    3944             :  * algebraic form. */
    3945             : GEN
    3946       65213 : Buchall_param(GEN P, double cbach, double cbach2, long Nrelid, long max_fact, long idex, long nbthr, long flag, long prec)
    3947             : {
    3948             :   pari_timer T;
    3949       65213 :   pari_sp av0 = avma, av, av2;
    3950             :   long PREC, N, R1, R2, RU, low, high, LIMC0, LIMC, LIMC2, LIMCMAX, zc, i;
    3951       65213 :   long LIMres, bit = 0, flag_nfinit = 0, nfisclone = 0;
    3952       65213 :   long nreldep, sfb_trials, need, old_need, precdouble = 0, TRIES = 0;
    3953             :   long done_small, small_fail, fail_limit, squash_index;
    3954             :   double LOGD, LOGD2, lim;
    3955       65213 :   GEN computed = NULL, fu = NULL, zu, nf, D, A, W, R, h, Ce, PERM;
    3956             :   GEN small_multiplier, auts, cyclic, embs, SUnits;
    3957             :   GEN res, L, invhr, B, C, lambda, dep, clg1, clg2, Vbase;
    3958       65213 :   const char *precpb = NULL;
    3959       65213 :   REL_t *old_cache = NULL;
    3960             :   nfmaxord_t nfT;
    3961             :   RELCACHE_t cache;
    3962             :   FB_t F;
    3963             :   GRHcheck_t GRHcheck;
    3964             :   FACT *fact;
    3965             : 
    3966       65213 :   if (DEBUGLEVEL) timer_start(&T);
    3967       65213 :   P = get_nfpol(P, &nf);
    3968       65193 :   if (degpol(P)==2) Nrelid = 0;
    3969       65193 :   if (nf)
    3970        3871 :     D = nf_get_disc(nf);
    3971             :   else
    3972             :   {
    3973       61322 :     nfinit_basic(&nfT, P);
    3974       61327 :     D = nfT.dK;
    3975       61327 :     if (!ZX_is_monic(nfT.T0))
    3976             :     {
    3977          14 :       pari_warn(warner,"nonmonic polynomial in bnfinit, using polredbest");
    3978          14 :       flag_nfinit = nf_RED;
    3979             :     }
    3980             :   }
    3981       65197 :   PREC = maxss(DEFAULTPREC, prec);
    3982       65199 :   N = degpol(P);
    3983       65198 :   if (N <= 1)
    3984             :   {
    3985        1204 :     if (!nf) nf = nfinit_complete(&nfT, flag_nfinit, PREC);
    3986        1204 :     return gc_GEN(av0, Buchall_deg1(nf));
    3987             :   }
    3988       63994 :   D = absi_shallow(D);
    3989       63994 :   LOGD = dbllog2(D) * M_LN2;
    3990       63994 :   LOGD2 = LOGD*LOGD;
    3991       63994 :   LIMCMAX = (long)(4.*LOGD2);
    3992       63994 :   if (nf) PREC = maxss(PREC, nf_get_prec(nf));
    3993       63994 :   PREC = maxss(PREC, nbits2prec((long)(LOGD2 * 0.02) + N*N));
    3994             : 
    3995       63994 :   if (nf) PREC = maxss(PREC, nf_get_prec(nf));
    3996       63994 :   PREC = maxss(PREC, nbits2prec((long)(LOGD2 * 0.02) + N*N));
    3997       63993 :   PREC = maxss(PREC, small_norm_prec(N, LOGD, LIMCMAX));
    3998       63993 :   if (DEBUGLEVEL) err_printf("PREC = %ld\n", PREC);
    3999             : 
    4000       63993 :   if (!nf)
    4001       60332 :     nf = nfinit_complete(&nfT, flag_nfinit, PREC);
    4002        3661 :   else if (nf_get_prec(nf) < PREC)
    4003         161 :     nf = nfnewprec_shallow(nf, PREC);
    4004       63999 :   zu = nfrootsof1(nf);
    4005       63996 :   gel(zu,2) = nf_to_scalar_or_alg(nf, gel(zu,2));
    4006             : 
    4007       63996 :   nf_get_sign(nf, &R1, &R2); RU = R1+R2;
    4008       63996 :   auts = automorphism_matrices(nf, &cyclic);
    4009       64000 :   F.embperm = automorphism_perms(nf_get_M(nf), auts, cyclic, R1, R2, N);
    4010       64000 :   if (DEBUGLEVEL)
    4011             :   {
    4012           0 :     timer_printf(&T, "nfinit & nfrootsof1");
    4013           0 :     err_printf("%s bnf: R1 = %ld, R2 = %ld\nD = %Ps\n",
    4014             :                flag? "Algebraic": "Floating point", R1,R2, D);
    4015             :   }
    4016       64000 :   if (LOGD < 20.)
    4017             :   { /* tiny disc, Minkowski may be smaller than Bach */
    4018       62537 :     lim = exp(-N + R2 * log(4/M_PI) + LOGD/2) * sqrt(2*M_PI*N);
    4019       62537 :     if (lim < 3) lim = 3;
    4020             :   }
    4021             :   else /* to be ignored */
    4022        1463 :     lim = -1;
    4023       64000 :   if (cbach > 12.) {
    4024           0 :     if (cbach2 < cbach) cbach2 = cbach;
    4025           0 :     cbach = 12.;
    4026             :   }
    4027       64000 :   if (cbach < 0.)
    4028           0 :     pari_err_DOMAIN("Buchall","Bach constant","<",gen_0,dbltor(cbach));
    4029             : 
    4030       64000 :   cache.base = NULL; F.subFB = NULL; F.LP = NULL; SUnits = Ce = NULL;
    4031       64000 :   init_GRHcheck(&GRHcheck, N, R1, LOGD);
    4032       64001 :   high = low = LIMC0 = maxss((long)(cbach2*LOGD2), 1);
    4033      312174 :   while (!GRHchk(nf, &GRHcheck, high)) { low = high; high *= 2; }
    4034      248216 :   while (high - low > 1)
    4035             :   {
    4036      184217 :     long test = (low+high)/2;
    4037      184217 :     if (GRHchk(nf, &GRHcheck, test)) high = test; else low = test;
    4038             :   }
    4039       63999 :   LIMC2 = (high == LIMC0+1 && GRHchk(nf, &GRHcheck, LIMC0))? LIMC0: high;
    4040       63999 :   if (LIMC2 > LIMCMAX) LIMC2 = LIMCMAX;
    4041             :   /* Assuming GRH, {P, NP <= LIMC2} generate Cl(K) */
    4042       63999 :   if (DEBUGLEVEL) err_printf("LIMC2 = %ld\n", LIMC2);
    4043       63999 :   LIMC0 = (long)(cbach*LOGD2); /* initial value for LIMC */
    4044       63999 :   LIMC = cbach? LIMC0: LIMC2; /* use {P, NP <= LIMC} as a factorbase */
    4045       63999 :   LIMC = maxss(LIMC, nthideal(&GRHcheck, nf, N));
    4046       64000 :   if (DEBUGLEVEL) timer_printf(&T, "computing Bach constant");
    4047       64000 :   LIMres = primeneeded(N, R1, R2, LOGD);
    4048       64001 :   cache_prime_dec(&GRHcheck, LIMres, nf);
    4049             :   /* invhr ~ 2^r1 (2pi)^r2 / sqrt(D) w * Res(zeta_K, s=1) = 1 / hR */
    4050      128000 :   invhr = gmul(gdiv(gmul2n(powru(mppi(DEFAULTPREC), R2), RU),
    4051       64000 :               mulri(gsqrt(D,DEFAULTPREC),gel(zu,1))),
    4052             :               compute_invres(&GRHcheck, LIMres));
    4053       64000 :   if (DEBUGLEVEL) timer_printf(&T, "computing inverse of hR");
    4054       64000 :   av = avma;
    4055             : 
    4056       66250 : START:
    4057       66250 :   if (DEBUGLEVEL) timer_start(&T);
    4058       66250 :   if (TRIES) LIMC = bnf_increase_LIMC(LIMC,LIMCMAX);
    4059       66250 :   if (DEBUGLEVEL && LIMC > LIMC0)
    4060           0 :     err_printf("%s*** Bach constant: %f\n", TRIES?"\n":"", LIMC/LOGD2);
    4061       66250 :   if (cache.base)
    4062             :   {
    4063             :     REL_t *rel;
    4064        3693 :     for (i = 1, rel = cache.base + 1; rel < cache.last; rel++)
    4065        3620 :       if (rel->m) i++;
    4066          73 :     computed = cgetg(i, t_VEC);
    4067        3693 :     for (i = 1, rel = cache.base + 1; rel < cache.last; rel++)
    4068        3620 :       if (rel->m) gel(computed, i++) = rel->m;
    4069          73 :     computed = gclone(computed); delete_cache(&cache);
    4070             :   }
    4071       66250 :   TRIES++; set_avma(av);
    4072       66250 :   if (F.LP) delete_FB(&F);
    4073       66250 :   if (LIMC2 < LIMC) LIMC2 = LIMC;
    4074       66250 :   if (DEBUGLEVEL) { err_printf("LIMC = %ld, LIMC2 = %ld\n",LIMC,LIMC2); }
    4075             : 
    4076       66250 :   FBgen(&F, nf, N, LIMC, LIMC2, &GRHcheck);
    4077       66247 :   if (!F.KC) goto START;
    4078       66247 :   av = avma;
    4079       66247 :   subFBgen(&F,auts,cyclic,lim < 0? LIMC2: mindd(lim,LIMC2),MINSFB);
    4080       66251 :   if (lg(F.subFB) == 1) goto START;
    4081       64074 :   if (DEBUGLEVEL)
    4082           0 :     timer_printf(&T, "factorbase (#subFB = %ld) and ideal permutations",
    4083           0 :                      lg(F.subFB)-1);
    4084             : 
    4085       64074 :   fact = (FACT*)stack_malloc((F.KC+1)*sizeof(FACT));
    4086       64074 :   PERM = leafcopy(F.perm); /* to be restored in case of precision increase */
    4087       64072 :   cache.basis = zero_Flm_copy(F.KC,F.KC);
    4088       64073 :   small_multiplier = zero_Flv(F.KC);
    4089       64073 :   done_small = small_fail = squash_index = zc = sfb_trials = nreldep = 0;
    4090       64073 :   fail_limit = F.KC + 1;
    4091       64073 :   W = A = R = NULL;
    4092       64073 :   av2 = avma;
    4093       64073 :   init_rel(&cache, &F, RELSUP + RU-1);
    4094       64074 :   old_need = need = cache.end - cache.last;
    4095       64074 :   add_cyclotomic_units(nf, zu, &cache, &F);
    4096       64073 :   if (DEBUGLEVEL) err_printf("\n");
    4097       64073 :   cache.end = cache.last + need;
    4098             : 
    4099       64073 :   if (computed)
    4100             :   {
    4101        1722 :     for (i = 1; i < lg(computed); i++)
    4102        1649 :       try_elt(&cache, &F, nf, gel(computed, i), fact);
    4103          73 :     gunclone(computed);
    4104          73 :     if (DEBUGLEVEL && i > 1)
    4105           0 :       timer_printf(&T, "including already computed relations");
    4106          73 :     need = 0;
    4107             :   }
    4108             : 
    4109             :   do
    4110             :   {
    4111             :     GEN Ar, C0;
    4112             :     do
    4113             :     {
    4114      122601 :       pari_sp av4 = avma;
    4115      122601 :       if (need > 0)
    4116             :       {
    4117      122448 :         long oneed = cache.end - cache.last;
    4118             :         /* Test below can be true if small_norm did not find enough linearly
    4119             :          * dependent relations */
    4120      122448 :         if (need < oneed) need = oneed;
    4121      122448 :         pre_allocate(&cache, need+lg(auts)-1+(R ? lg(W)-1 : 0));
    4122      122448 :         cache.end = cache.last + need;
    4123      122448 :         F.L_jid = trim_list(&F);
    4124             :       }
    4125      122600 :       if (need > 0 && Nrelid > 0 && (done_small <= F.KC+1 || A) &&
    4126       70353 :           small_fail <= fail_limit &&
    4127       70353 :           cache.last < cache.base + 2*F.KC+2*RU+RELSUP /* heuristic */)
    4128             :       {
    4129       66762 :         long j, k, LIE = (R && lg(W) > 1 && (done_small % 2));
    4130       66762 :         REL_t *last = cache.last;
    4131       66762 :         pari_sp av3 = avma;
    4132       66762 :         if (LIE)
    4133             :         { /* We have full rank for class group and unit. The following tries to
    4134             :            * improve the prime group lattice by looking for relations involving
    4135             :            * the primes generating the class group. */
    4136        3393 :           long n = lg(W)-1; /* need n relations to squash the class group */
    4137        3393 :           F.L_jid = vecslice(F.perm, 1, n);
    4138        3393 :           cache.end = cache.last + n;
    4139             :           /* Lie to the add_rel subsystem: pretend we miss relations involving
    4140             :            * the primes generating the class group (and only those). */
    4141        3393 :           cache.missing = n;
    4142       10620 :           for ( ; n > 0; n--) mael(cache.basis, F.perm[n], F.perm[n]) = 0;
    4143             :         }
    4144       66762 :         j = done_small % (F.KC+1);
    4145       66762 :         if (j && !A)
    4146             :         { /* Prevent considering both P_iP_j and P_jP_i in small_norm */
    4147             :           /* Not all elements end up in F.L_jid (eliminated by hnfspec/add or
    4148             :            * by trim_list): keep track of which ideals are being considered
    4149             :            * at each run. */
    4150         414 :           long mj = small_multiplier[j];
    4151        6569 :           for (i = k = 1; i < lg(F.L_jid); i++)
    4152        6155 :             if (F.L_jid[i] > mj)
    4153             :             {
    4154        6155 :               small_multiplier[F.L_jid[i]] = j;
    4155        6155 :               F.L_jid[k++] = F.L_jid[i];
    4156             :             }
    4157         414 :           setlg(F.L_jid, k);
    4158             :         }
    4159       66762 :         if (lg(F.L_jid) > 1) small_norm(&cache, &F, nf, Nrelid, max_fact, idex, nbthr, fact, j);
    4160       66764 :         F.L_jid = F.perm; set_avma(av3);
    4161       66764 :         if (!A && cache.last != last) small_fail = 0; else small_fail++;
    4162       66764 :         if (LIE)
    4163             :         { /* restore add_rel subsystem: undo above lie */
    4164        3393 :           long n = lg(W) - 1;
    4165       10620 :           for ( ; n > 0; n--) mael(cache.basis, F.perm[n], F.perm[n]) = 1;
    4166        3393 :           cache.missing = 0;
    4167             :         }
    4168       66764 :         cache.end = cache.last;
    4169       66764 :         done_small++;
    4170       66764 :         need = F.sfb_chg = 0;
    4171             :       }
    4172      122602 :       if (need > 0)
    4173             :       { /* Random relations */
    4174       55685 :         if (++nreldep > F.MAXDEPSIZESFB) {
    4175          14 :           if (++sfb_trials > SFB_MAX && LIMC < LIMCMAX/2) goto START;
    4176          14 :           F.sfb_chg = sfb_INCREASE;
    4177          14 :           nreldep = 0;
    4178             :         }
    4179       55671 :         else if (!(nreldep % F.MAXDEPSFB))
    4180       26405 :           F.sfb_chg = sfb_CHANGE;
    4181       55685 :         if (F.sfb_chg && !subFB_change(&F)) goto START;
    4182       55612 :         rnd_rel(&cache, &F, nf, max_fact, nbthr, fact);
    4183       55613 :         F.L_jid = F.perm;
    4184             :       }
    4185      122530 :       if (DEBUGLEVEL) timer_start(&T);
    4186      122530 :       if (precpb)
    4187             :       {
    4188             :         REL_t *rel;
    4189          80 :         if (DEBUGLEVEL)
    4190             :         {
    4191           0 :           char str[64]; sprintf(str,"Buchall_param (%s)",precpb);
    4192           0 :           pari_warn(warnprec,str,PREC);
    4193             :         }
    4194          80 :         nf = _nfnewprec(nf, PREC, &nfisclone);
    4195          80 :         precdouble++; precpb = NULL;
    4196             : 
    4197          80 :         if (flag)
    4198             :         { /* recompute embs only, no need to redo HNF */
    4199          38 :           long j, le = lg(embs), lC = lg(C);
    4200          38 :           GEN E, M = nf_get_M(nf);
    4201          38 :           set_avma(av4);
    4202       12611 :           for (rel = cache.base+1, i = 1; i < le; i++,rel++)
    4203       12573 :             gel(embs,i) = rel_embed(rel, &F, embs, i, M, RU, R1, PREC);
    4204          38 :           E = RgM_ZM_mul(embs, rowslice(C, RU+1, nbrows(C)));
    4205       12611 :           for (j = 1; j < lC; j++)
    4206       65595 :             for (i = 1; i <= RU; i++) gcoeff(C,i,j) = gcoeff(E,i,j);
    4207          38 :           av4 = avma;
    4208             :         }
    4209             :         else
    4210             :         { /* recompute embs + HNF */
    4211       10318 :           for(i = 1; i < lg(PERM); i++) F.perm[i] = PERM[i];
    4212          42 :           cache.chk = cache.base;
    4213          42 :           W = NULL;
    4214             :         }
    4215          80 :         if (DEBUGLEVEL) timer_printf(&T, "increasing accuracy");
    4216             :       }
    4217      122530 :       set_avma(av4);
    4218      122530 :       if (cache.chk != cache.last)
    4219             :       { /* Reduce relation matrices */
    4220      122410 :         long l = cache.last - cache.chk + 1, j;
    4221      122410 :         GEN mat = cgetg(l, t_MAT);
    4222             :         REL_t *rel;
    4223             : 
    4224     1126924 :         for (j=1,rel = cache.chk + 1; j < l; rel++,j++) gel(mat,j) = rel->R;
    4225      122408 :         if (!flag || W)
    4226             :         {
    4227       59924 :           embs = get_embs(&F, &cache, nf, embs, PREC);
    4228       59924 :           if (DEBUGLEVEL && timer_get(&T) > 1)
    4229           0 :             timer_printf(&T, "floating point embeddings");
    4230             :         }
    4231      122409 :         if (!W)
    4232             :         { /* never reduced before */
    4233       64116 :           C = flag? matbotid(&cache): embs;
    4234       64115 :           W = hnfspec_i(mat, F.perm, &dep, &B, &C, F.subFB ? lg(F.subFB)-1:0);
    4235       64116 :           if (DEBUGLEVEL)
    4236           0 :             timer_printf(&T, "hnfspec [%ld x %ld]", lg(F.perm)-1, l-1);
    4237       64116 :           if (flag)
    4238             :           {
    4239       62485 :             PREC += nbits2extraprec(gexpo(C));
    4240       62485 :             if (nf_get_prec(nf) < PREC) nf = _nfnewprec(nf, PREC, &nfisclone);
    4241       62485 :             embs = get_embs(&F, &cache, nf, embs, PREC);
    4242       62485 :             C = vconcat(RgM_ZM_mul(embs, C), C);
    4243             :           }
    4244       64116 :           if (DEBUGLEVEL)
    4245           0 :             timer_printf(&T, "hnfspec floating points");
    4246             :         }
    4247             :         else
    4248             :         {
    4249       58293 :           long k = lg(embs);
    4250       58293 :           GEN E = vecslice(embs, k-l+1,k-1);
    4251       58294 :           if (flag)
    4252             :           {
    4253       55507 :             E = matbotidembs(&cache, E);
    4254       55507 :             matenlarge(C, cache.last - cache.chk);
    4255             :           }
    4256       58294 :           W = hnfadd_i(W, F.perm, &dep, &B, &C, mat, E);
    4257       58293 :           if (DEBUGLEVEL)
    4258           0 :             timer_printf(&T, "hnfadd (%ld + %ld)", l-1, lg(dep)-1);
    4259             :         }
    4260      122409 :         (void)gc_all(av2, 5, &W,&C,&B,&dep,&embs);
    4261      122410 :         cache.chk = cache.last;
    4262             :       }
    4263         120 :       else if (!W)
    4264             :       {
    4265           0 :         need = old_need;
    4266           0 :         F.L_jid = vecslice(F.perm, 1, need);
    4267           0 :         continue;
    4268             :       }
    4269      122530 :       need = F.KC - (lg(W)-1) - (lg(B)-1);
    4270      122530 :       if (!need && cache.missing)
    4271             :       { /* The test above will never be true except if 27449|class number.
    4272             :          * Ensure that if we have maximal rank for the ideal lattice, then
    4273             :          * cache.missing == 0. */
    4274          14 :         for (i = 1; cache.missing; i++)
    4275           7 :           if (!mael(cache.basis, i, i))
    4276             :           {
    4277             :             long j;
    4278           7 :             cache.missing--; mael(cache.basis, i, i) = 1;
    4279         427 :             for (j = i+1; j <= F.KC; j++) mael(cache.basis, j, i) = 0;
    4280             :           }
    4281             :       }
    4282      122530 :       zc = (lg(C)-1) - (lg(B)-1) - (lg(W)-1);
    4283      122530 :       if (RU-1-zc > 0) need = minss(need + RU-1-zc, F.KC); /* for units */
    4284      122530 :       if (need)
    4285             :       { /* dependent rows */
    4286         811 :         F.L_jid = vecslice(F.perm, 1, need);
    4287         811 :         vecsmall_sort(F.L_jid);
    4288         811 :         if (need != old_need) { nreldep = 0; old_need = need; }
    4289             :       }
    4290             :       else
    4291             :       { /* If the relation lattice is too small, check will be > 1 and we will
    4292             :          * do a new run of small_norm/rnd_rel asking for 1 relation. This often
    4293             :          * gives a relation involving L_jid[1]. We rotate the first element of
    4294             :          * L_jid in order to increase the probability of finding relations that
    4295             :          * increases the lattice. */
    4296      121719 :         long j, n = lg(W) - 1;
    4297      121719 :         if (n > 1 && squash_index % n)
    4298             :         {
    4299        9025 :           F.L_jid = leafcopy(F.perm);
    4300       36564 :           for (j = 1; j <= n; j++)
    4301       27539 :             F.L_jid[j] = F.perm[1 + (j + squash_index - 1) % n];
    4302             :         }
    4303             :         else
    4304      112694 :           F.L_jid = F.perm;
    4305      121719 :         squash_index++;
    4306             :       }
    4307             :     }
    4308      122530 :     while (need);
    4309             : 
    4310      121719 :     if (!A)
    4311             :     {
    4312       64081 :       small_fail = old_need = 0;
    4313       64081 :       fail_limit = maxss(F.KC / FAIL_DIVISOR, MINFAIL);
    4314             :     }
    4315      121719 :     A = vecslice(C, 1, zc); /* cols corresponding to units */
    4316      121718 :     if (flag) A = rowslice(A, 1, RU);
    4317      121718 :     Ar = real_i(A);
    4318      121719 :     R = compute_multiple_of_R(Ar, RU, N, &need, &bit, &lambda);
    4319      121719 :     if (need < old_need) small_fail = 0;
    4320             : #if 0 /* A good idea if we are indeed stuck but needs tuning */
    4321             :     /* we have computed way more relations than should be necessary */
    4322             :     if (TRIES < 3 && LIMC < LIMCMAX / 8 &&
    4323             :                      cache.last - cache.base > 10 * F.KC) goto START;
    4324             : #endif
    4325      121719 :     old_need = need;
    4326      121719 :     if (!lambda)
    4327          11 :     { precpb = "bestappr"; PREC = myprecdbl(PREC, flag? C: NULL); continue; }
    4328      121708 :     if (!R)
    4329             :     { /* not full rank for units */
    4330       25361 :       if (!need)
    4331           0 :       { precpb = "regulator"; PREC = myprecdbl(PREC, flag? C: NULL); }
    4332       25361 :       continue;
    4333             :     }
    4334       96347 :     if (cache.last==old_cache) { need=1; continue; }
    4335       96263 :     old_cache = cache.last;
    4336       96263 :     h = ZM_det_triangular(W);
    4337       96263 :     if (DEBUGLEVEL) err_printf("\n#### Tentative class number: %Ps\n", h);
    4338       96263 :     i = compute_R(lambda, mulir(h,invhr), &L, &R);
    4339       96260 :     if (DEBUGLEVEL)
    4340             :     {
    4341           0 :       err_printf("\n");
    4342           0 :       timer_printf(&T, "computing regulator and check");
    4343             :     }
    4344       96260 :     switch(i)
    4345             :     {
    4346       32192 :       case fupb_RELAT:
    4347       32192 :         need = 1; /* not enough relations */
    4348       32192 :         continue;
    4349          62 :       case fupb_PRECI: /* prec problem unless we cheat on Bach constant */
    4350          62 :         if ((precdouble&7) == 7 && LIMC <= LIMCMAX/2) goto START;
    4351          62 :         precpb = "compute_R"; PREC = myprecdbl(PREC, flag? C: NULL);
    4352          62 :         continue;
    4353             :     }
    4354             :     /* DONE */
    4355             : 
    4356       64006 :     if (F.KCZ2 > F.KCZ)
    4357             :     {
    4358           7 :       if (F.sfb_chg && !subFB_change(&F)) goto START;
    4359           7 :       if (!be_honest(&F, nf, auts, fact)) goto START;
    4360           7 :       if (DEBUGLEVEL) timer_printf(&T, "to be honest");
    4361             :     }
    4362       64006 :     F.KCZ2 = 0; /* be honest only once */
    4363             : 
    4364             :     /* fundamental units */
    4365             :     {
    4366       64006 :       GEN AU, CU, U, v = extract_full_lattice(L); /* L may be large */
    4367       64007 :       CU = NULL;
    4368       64007 :       if (v) { A = vecpermute(A, v); L = vecpermute(L, v); }
    4369             :       /* arch. components of fund. units */
    4370       64007 :       U = ZM_lll(L, 0.99, LLL_IM);
    4371       64008 :       U = ZM_mul(U, lll(RgM_ZM_mul(real_i(A), U)));
    4372       64008 :       if (DEBUGLEVEL) timer_printf(&T, "units LLL");
    4373       64008 :       AU = RgM_ZM_mul(A, U);
    4374       64008 :       A = cleanarchunit(AU, N, NULL, PREC);
    4375       64008 :       if (RU > 1 /* if there are fund units, test we have correct regulator */
    4376       48797 :           && (!A || lg(A) < RU || expo(subrr(get_regulator(A), R)) > -1))
    4377           7 :       {
    4378           7 :         long add = nbits2extraprec( gexpo(AU) + 64 ) - gprecision(AU);
    4379           7 :         long t = maxss(PREC * 0.15, add);
    4380           7 :         if (!A && DEBUGLEVEL) err_printf("### Incorrect units lognorm");
    4381           7 :         precpb = "cleanarch"; PREC += maxss(t, EXTRAPREC64); continue;
    4382             :       }
    4383       64000 :       if (flag)
    4384             :       {
    4385       62425 :         long l = lgcols(C) - RU;
    4386             :         REL_t *rel;
    4387       62425 :         SUnits = cgetg(l, t_COL);
    4388     1011070 :         for (rel = cache.base+1, i = 1; i < l; i++,rel++)
    4389      948644 :           set_rel_alpha(rel, auts, SUnits, i);
    4390       62426 :         if (RU > 1)
    4391             :         {
    4392       47712 :           GEN c = v? vecpermute(C,v): vecslice(C,1,zc);
    4393       47712 :           CU = ZM_mul(rowslice(c, RU+1, nbrows(c)), U);
    4394             :         }
    4395             :       }
    4396       64001 :       if (DEBUGLEVEL) err_printf("\n#### Computing fundamental units\n");
    4397       64001 :       fu = getfu(nf, &A, CU? &U: NULL, PREC);
    4398       64001 :       CU = CU? ZM_mul(CU, U): cgetg(1, t_MAT);
    4399       64001 :       if (DEBUGLEVEL) timer_printf(&T, "getfu");
    4400       64001 :       Ce = vecslice(C, zc+1, lg(C)-1);
    4401       64001 :       if (flag) SUnits = mkvec4(SUnits, CU, rowslice(Ce, RU+1, nbrows(Ce)),
    4402             :                                 utoipos(LIMC));
    4403             :     }
    4404             :     /* class group generators */
    4405       64001 :     if (flag) Ce = rowslice(Ce, 1, RU);
    4406       64001 :     C0 = Ce; Ce = cleanarch(Ce, N, NULL, PREC);
    4407       64000 :     if (!Ce) {
    4408           0 :       long add = nbits2extraprec( gexpo(C0) + 64 ) - gprecision(C0);
    4409           0 :       precpb = "cleanarch"; PREC += maxss(add, 1);
    4410             :     }
    4411       64000 :     if (DEBUGLEVEL) timer_printf(&T, "cleanarch");
    4412      121717 :   } while (need || precpb);
    4413             : 
    4414       64000 :   Vbase = vecpermute(F.LP, F.perm);
    4415       64001 :   if (!fu) fu = cgetg(1, t_MAT);
    4416       64001 :   if (!SUnits) SUnits = gen_1;
    4417       64001 :   clg1 = class_group_gen(nf,W,Ce,Vbase,PREC, &clg2);
    4418       64001 :   res = mkvec5(clg1, R, SUnits, zu, fu);
    4419       64001 :   res = buchall_end(nf,res,clg2,W,B,A,Ce,Vbase);
    4420       64001 :   delete_FB(&F);
    4421       64001 :   res = gc_GEN(av0, res);
    4422       64001 :   if (flag) obj_insert_shallow(res, MATAL, cgetg(1,t_VEC));
    4423       64001 :   if (nfisclone) gunclone(nf);
    4424       64001 :   delete_cache(&cache);
    4425       64001 :   free_GRHcheck(&GRHcheck);
    4426       64001 :   return res;
    4427             : }

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