Esempio n. 1
0
static GEN
bound_for_coeff(long m, GEN rr, GEN *maxroot)
{
  long i,r1, lrr=lg(rr);
  GEN p1,b1,b2,B,M, C = matpascal(m-1);

  for (r1=1; r1 < lrr; r1++)
    if (typ(rr[r1]) != t_REAL) break;
  r1--;

  rr = gabs(rr,0); *maxroot = vecmax(rr);
  for (i=1; i<lrr; i++)
    if (gcmp(gel(rr,i), gen_1) < 0) gel(rr,i) = gen_1;
  for (b1=gen_1,i=1; i<=r1; i++) b1 = gmul(b1, gel(rr,i));
  for (b2=gen_1    ; i<lrr; i++) b2 = gmul(b2, gel(rr,i));
  B = gmul(b1, gsqr(b2)); /* Mahler measure */
  M = cgetg(m+2, t_VEC); gel(M,1) = gel(M,2) = gen_0; /* unused */
  for (i=1; i<m; i++)
  {
    p1 = gadd(gmul(gcoeff(C, m, i+1), B),/* binom(m-1, i)   */
              gcoeff(C, m, i));          /* binom(m-1, i-1) */
    gel(M,i+2) = ceil_safe(p1);
  }
  return M;
}
Esempio n. 2
0
/* return a bound for T_2(P), P | polbase in C[X]
 * NB: Mignotte bound: A | S ==>
 *  |a_i| <= binom(d-1, i-1) || S ||_2 + binom(d-1, i) lc(S)
 *
 * Apply to sigma(S) for all embeddings sigma, then take the L_2 norm over
 * sigma, then take the sup over i.
 **/
static GEN
nf_Mignotte_bound(GEN nf, GEN polbase)
{
  GEN G = gmael(nf,5,2), lS = leading_term(polbase); /* t_INT */
  GEN p1, C, N2, matGS, binlS, bin;
  long prec, i, j, d = degpol(polbase), n = degpol(nf[1]), r1 = nf_get_r1(nf);

  binlS = bin = vecbinome(d-1);
  if (!gcmp1(lS)) binlS = gmul(lS, bin);

  N2 = cgetg(n+1, t_VEC);
  prec = gprecision(G);
  for (;;)
  {
    nffp_t F;

    matGS = cgetg(d+2, t_MAT);
    for (j=0; j<=d; j++) gel(matGS,j+1) = arch_for_T2(G, gel(polbase,j+2));
    matGS = shallowtrans(matGS);
    for (j=1; j <= r1; j++) /* N2[j] = || sigma_j(S) ||_2 */
    {
      gel(N2,j) = gsqrt( QuickNormL2(gel(matGS,j), DEFAULTPREC), DEFAULTPREC );
      if (lg(N2[j]) < DEFAULTPREC) goto PRECPB;
    }
    for (   ; j <= n; j+=2)
    {
      GEN q1 = QuickNormL2(gel(matGS,j  ), DEFAULTPREC);
      GEN q2 = QuickNormL2(gel(matGS,j+1), DEFAULTPREC);
      p1 = gmul2n(mpadd(q1, q2), -1);
      gel(N2,j) = gel(N2,j+1) = gsqrt( p1, DEFAULTPREC );
      if (lg(N2[j]) < DEFAULTPREC) goto PRECPB;
    }
    if (j > n) break; /* done */
PRECPB:
    prec = (prec<<1)-2;
    remake_GM(nf, &F, prec); G = F.G;
    if (DEBUGLEVEL>1) pari_warn(warnprec, "nf_factor_bound", prec);
  }

  /* Take sup over 0 <= i <= d of
   * sum_sigma | binom(d-1, i-1) ||sigma(S)||_2 + binom(d-1,i) lc(S) |^2 */

  /* i = 0: n lc(S)^2 */
  C = mulsi(n, sqri(lS));
  /* i = d: sum_sigma ||sigma(S)||_2^2 */
  p1 = gnorml2(N2); if (gcmp(C, p1) < 0) C = p1;
  for (i = 1; i < d; i++)
  {
    GEN s = gen_0;
    for (j = 1; j <= n; j++)
    {
      p1 = mpadd( mpmul(gel(bin,i), gel(N2,j)), gel(binlS,i+1) );
      s = mpadd(s, gsqr(p1));
    }
    if (gcmp(C, s) < 0) C = s;
  }
  return C;
}
Esempio n. 3
0
static void
bestlift_init(long a, GEN nf, GEN pr, GEN C, nflift_t *L)
{
  const long D = 100;
  const double alpha = ((double)D-1) / D; /* LLL parameter */
  const long d = degpol(nf[1]);
  pari_sp av = avma;
  GEN prk, PRK, B, GSmin, pk;
  pari_timer ti;

  TIMERstart(&ti);
  if (!a) a = (long)bestlift_bound(C, d, alpha, pr_norm(pr));

  for (;; avma = av, a<<=1)
  {
    if (DEBUGLEVEL>2) fprintferr("exponent: %ld\n",a);
    PRK = prk = idealpows(nf, pr, a);
    pk = gcoeff(prk,1,1);
    /* reduce size first, "scramble" matrix */
    PRK = lllintpartial_ip(PRK);
    /* now floating point reduction is fast */
    PRK = lllint_fp_ip(PRK, 4);
    PRK = lllint_i(PRK, D, 0, NULL, NULL, &B);
    if (!PRK) { PRK = prk; GSmin = pk; } /* nf = Q */
    else
    {
      pari_sp av2 = avma;
      GEN S = invmat( get_R(PRK) ), BB = GS_norms(B, DEFAULTPREC);
      GEN smax = gen_0;
      long i, j;
      for (i=1; i<=d; i++)
      {
        GEN s = gen_0;
        for (j=1; j<=d; j++)
          s = gadd(s, gdiv( gsqr(gcoeff(S,i,j)), gel(BB,j)));
        if (gcmp(s, smax) > 0) smax = s;
      }
      GSmin = gerepileupto(av2, ginv(gmul2n(smax, 2)));
    }
    if (gcmp(GSmin, C) >= 0) break;
  }
  if (DEBUGLEVEL>2)
    fprintferr("for this exponent, GSmin = %Z\nTime reduction: %ld\n",
      GSmin, TIMER(&ti));
  L->k = a;
  L->den = L->pk = pk;
  L->prk = PRK;
  L->iprk = ZM_inv(PRK, pk);
  L->GSmin= GSmin;
  L->prkHNF = prk;
  init_proj(L, gel(nf,1), gel(pr,1));
}
Esempio n. 4
0
File: aprcl.c Progetto: jpflori/pari
static GEN
sqrmod(GEN x, Red *R) {
  return R->red(gsqr(x), R);
}
Esempio n. 5
0
/* Naive recombination of modular factors: combine up to maxK modular
 * factors, degree <= klim and divisible by hint
 *
 * target = polynomial we want to factor
 * famod = array of modular factors.  Product should be congruent to
 * target/lc(target) modulo p^a
 * For true factors: S1,S2 <= p^b, with b <= a and p^(b-a) < 2^31 */
static GEN
nfcmbf(nfcmbf_t *T, GEN p, long a, long maxK, long klim)
{
  GEN pol = T->pol, nf = T->nf, famod = T->fact, dn = T->dn;
  GEN bound = T->bound;
  GEN nfpol = gel(nf,1);
  long K = 1, cnt = 1, i,j,k, curdeg, lfamod = lg(famod)-1, dnf = degpol(nfpol);
  GEN res = cgetg(3, t_VEC);
  pari_sp av0 = avma;
  GEN pk = gpowgs(p,a), pks2 = shifti(pk,-1);

  GEN ind      = cgetg(lfamod+1, t_VECSMALL);
  GEN degpol   = cgetg(lfamod+1, t_VECSMALL);
  GEN degsofar = cgetg(lfamod+1, t_VECSMALL);
  GEN listmod  = cgetg(lfamod+1, t_COL);
  GEN fa       = cgetg(lfamod+1, t_COL);
  GEN lc = absi(leading_term(pol)), lt = is_pm1(lc)? NULL: lc;
  GEN C2ltpol, C = T->L->topowden, Tpk = T->L->Tpk;
  GEN Clt  = mul_content(C, lt);
  GEN C2lt = mul_content(C,Clt);
  const double Bhigh = get_Bhigh(lfamod, dnf);
  trace_data _T1, _T2, *T1, *T2;
  pari_timer ti;

  TIMERstart(&ti);

  if (maxK < 0) maxK = lfamod-1;

  C2ltpol = C2lt? gmul(C2lt,pol): pol;
  {
    GEN q = ceil_safe(sqrtr(T->BS_2));
    GEN t1,t2, ltdn, lt2dn;
    GEN trace1   = cgetg(lfamod+1, t_MAT);
    GEN trace2   = cgetg(lfamod+1, t_MAT);

    ltdn = mul_content(lt, dn);
    lt2dn= mul_content(ltdn, lt);

    for (i=1; i <= lfamod; i++)
    {
      pari_sp av = avma;
      GEN P = gel(famod,i);
      long d = degpol(P);

      degpol[i] = d; P += 2;
      t1 = gel(P,d-1);/* = - S_1 */
      t2 = gsqr(t1);
      if (d > 1) t2 = gsub(t2, gmul2n(gel(P,d-2), 1));
      /* t2 = S_2 Newton sum */
      t2 = typ(t2)!=t_INT? FpX_rem(t2, Tpk, pk): modii(t2, pk);
      if (lt)
      {
        if (typ(t2)!=t_INT) {
          t1 = FpX_red(gmul(ltdn, t1), pk);
          t2 = FpX_red(gmul(lt2dn,t2), pk);
        } else {
          t1 = remii(mulii(ltdn, t1), pk);
          t2 = remii(mulii(lt2dn,t2), pk);
        }
      }
      gel(trace1,i) = gclone( nf_bestlift(t1, NULL, T->L) );
      gel(trace2,i) = gclone( nf_bestlift(t2, NULL, T->L) ); avma = av;
    }
    T1 = init_trace(&_T1, trace1, T->L, q);
    T2 = init_trace(&_T2, trace2, T->L, q);
    for (i=1; i <= lfamod; i++) { 
      gunclone(gel(trace1,i));
      gunclone(gel(trace2,i));
    }
  }
  degsofar[0] = 0; /* sentinel */

  /* ind runs through strictly increasing sequences of length K,
   * 1 <= ind[i] <= lfamod */
nextK:
  if (K > maxK || 2*K > lfamod) goto END;
  if (DEBUGLEVEL > 3)
    fprintferr("\n### K = %d, %Z combinations\n", K,binomial(utoipos(lfamod), K));
  setlg(ind, K+1); ind[1] = 1;
  i = 1; curdeg = degpol[ind[1]];
  for(;;)
  { /* try all combinations of K factors */
    for (j = i; j < K; j++)
    {
      degsofar[j] = curdeg;
      ind[j+1] = ind[j]+1; curdeg += degpol[ind[j+1]];
    }
    if (curdeg <= klim && curdeg % T->hint == 0) /* trial divide */
    {
      GEN t, y, q, list;
      pari_sp av;

      av = avma;
      /* d - 1 test */
      if (T1)
      {
        t = get_trace(ind, T1);
        if (rtodbl(QuickNormL2(t,DEFAULTPREC)) > Bhigh)
        {
          if (DEBUGLEVEL>6) fprintferr(".");
          avma = av; goto NEXT;
        }
      }
      /* d - 2 test */
      if (T2)
      {
        t = get_trace(ind, T2);
        if (rtodbl(QuickNormL2(t,DEFAULTPREC)) > Bhigh)
        {
          if (DEBUGLEVEL>3) fprintferr("|");
          avma = av; goto NEXT;
        }
      }
      avma = av;
      y = lt; /* full computation */
      for (i=1; i<=K; i++)
      {
        GEN q = gel(famod, ind[i]);
        if (y) q = gmul(y, q);
        y = FqX_centermod(q, Tpk, pk, pks2);
      }
      y = nf_pol_lift(y, bound, T);
      if (!y)
      {
        if (DEBUGLEVEL>3) fprintferr("@");
        avma = av; goto NEXT;
      }
      /* try out the new combination: y is the candidate factor */
      q = RgXQX_divrem(C2ltpol, y, nfpol, ONLY_DIVIDES);
      if (!q)
      {
        if (DEBUGLEVEL>3) fprintferr("*");
        avma = av; goto NEXT;
      }

      /* found a factor */
      list = cgetg(K+1, t_VEC);
      gel(listmod,cnt) = list;
      for (i=1; i<=K; i++) list[i] = famod[ind[i]];

      y = Q_primpart(y);
      gel(fa,cnt++) = QXQX_normalize(y, nfpol);
      /* fix up pol */
      pol = q;
      for (i=j=k=1; i <= lfamod; i++)
      { /* remove used factors */
        if (j <= K && i == ind[j]) j++;
        else
        {
          famod[k] = famod[i];
          update_trace(T1, k, i);
          update_trace(T2, k, i);
          degpol[k] = degpol[i]; k++;
        }
      }
      lfamod -= K;
      if (lfamod < 2*K) goto END;
      i = 1; curdeg = degpol[ind[1]];

      if (C2lt) pol = Q_primpart(pol);
      if (lt) lt = absi(leading_term(pol));
      Clt  = mul_content(C, lt);
      C2lt = mul_content(C,Clt);
      C2ltpol = C2lt? gmul(C2lt,pol): pol;
      if (DEBUGLEVEL > 2)
      {
        fprintferr("\n"); msgTIMER(&ti, "to find factor %Z",y);
        fprintferr("remaining modular factor(s): %ld\n", lfamod);
      }
      continue;
    }

NEXT:
    for (i = K+1;;)
    {
      if (--i == 0) { K++; goto nextK; }
      if (++ind[i] <= lfamod - K + i)
      {
        curdeg = degsofar[i-1] + degpol[ind[i]];
        if (curdeg <= klim) break;
      }
    }
  }
END:
  if (degpol(pol) > 0)
  { /* leftover factor */
    if (signe(leading_term(pol)) < 0) pol = gneg_i(pol);

    if (C2lt && lfamod < 2*K) pol = QXQX_normalize(Q_primpart(pol), nfpol);
    setlg(famod, lfamod+1);
    gel(listmod,cnt) = shallowcopy(famod);
    gel(fa,cnt++) = pol;
  }
  if (DEBUGLEVEL>6) fprintferr("\n");
  if (cnt == 2) { 
    avma = av0; 
    gel(res,1) = mkvec(T->pol);
    gel(res,2) = mkvec(T->fact);
  }
  else
  {
    setlg(listmod, cnt); setlg(fa, cnt);
    gel(res,1) = fa;
    gel(res,2) = listmod;
    res = gerepilecopy(av0, res);
  }
  return res;
}
Esempio n. 6
0
void mimc_perm_gadget<field_type>::snark_perm() {
  
  field_type x = input_state;
  field_type tmp;
 
 
  int index = varCount;
  index += 1;

  //mimc_snarkboard<field_type> pb;
  snarkvar<field_type> X, Y, Z;


  for(int i = 0;i < num_round;i++) {
    
    linear_term<field_type> u(0, fONE, key);
    X.add_var(u);
    u.reset(index, fONE, x);
    index++;
    X.add_var(u);
    Y.clear();
    Y = X;
    u.reset(index, fONE, fZERO);
    Z.clear();
    Z.add_var(u);
    index++;

    // std::cout<<"BEFORE SQR\n\n";
    // std::cout<<"X ->\n";X.print_snarkvar();
    // std::cout<<"Y ->\n";Y.print_snarkvar();
    // std::cout<<"Z ->\n";Z.print_snarkvar();

    f2n_sqr_gadget<field_type> gsqr(&X, &Z, mptr);
    gsqr.generate_r1cs_constraint();
    gsqr.generate_r1cs_witness();

    // std::cout<<"AFTER SQR\n\n";
    // std::cout<<"X ->\n";X.print_snarkvar();
    // std::cout<<"Y ->\n";Y.print_snarkvar();
    // std::cout<<"Z ->\n";Z.print_snarkvar();

    Z.lc[0].var_val = Z.lc_val;
    X.clear();
    X = Z;
    Z.clear();
    u.reset(index, fONE, fZERO);
    Z.add_var(u);

    // std::cout<<"BEFORE MUL\n\n";
    // std::cout<<"X ->\n";X.print_snarkvar();
    // std::cout<<"Y ->\n";Y.print_snarkvar();
    // std::cout<<"Z ->\n";Z.print_snarkvar();

    f2n_mul_gadget<field_type> gmul(&X, &Y, &Z, mptr);
    gmul.generate_r1cs_constraint();
    gmul.generate_r1cs_witness();

    // std::cout<<"AFTER MUL\n\n";
    // std::cout<<"X ->\n";X.print_snarkvar();
    // std::cout<<"Y ->\n";Y.print_snarkvar();
    // std::cout<<"Z ->\n";Z.print_snarkvar();

    X.clear();
    x = Z.lc_val;
    Y.clear();
  }
  
}