fix log table for large moduli + add order 2 & 3

This commit is contained in:
Pascal 2016-03-15 15:39:26 +01:00
parent 387c7f19e3
commit 32a1c966b9
12 changed files with 214 additions and 87 deletions

22
dlog.h
View file

@ -32,7 +32,7 @@
enum
{
DLOG_MODPE, DLOG_CRT, DLOG_POWER, DLOG_BSGS, DLOG_TABLE
DLOG_MODPE, DLOG_CRT, DLOG_POWER, DLOG_BSGS, DLOG_TABLE, DLOG_23
};
typedef struct dlog_precomp_struct dlog_precomp_struct;
@ -139,12 +139,15 @@ dlog_power_struct;
typedef dlog_power_struct dlog_power_t[1];
typedef ulong dlog_order23_t[1];
/* generic decomposition */
/*typedef */
struct
dlog_precomp_struct
{
int type;
ulong cost;
union
{
dlog_table_t table;
@ -152,20 +155,23 @@ dlog_precomp_struct
dlog_crt_t crt;
dlog_power_t power;
dlog_modpe_t modpe;
dlog_order23_t order23;
} t;
};
typedef dlog_precomp_struct dlog_precomp_t[1];
void dlog_table_init(dlog_table_t t, ulong a, ulong mod);
ulong dlog_order23_init(dlog_order23_t t, ulong a);
ulong dlog_table_init(dlog_table_t t, ulong a, ulong mod);
ulong dlog_crt_init(dlog_crt_t t, ulong a, ulong mod, ulong n, ulong num);
ulong dlog_power_init(dlog_power_t t, ulong a, ulong mod, ulong p, ulong e, ulong num);
ulong dlog_modpe_init(dlog_modpe_t t, ulong a, ulong p, ulong e, ulong pe, ulong num);
ulong dlog_bsgs_init(dlog_bsgs_t t, ulong a, ulong mod, ulong n, ulong m);
void dlog_1modpe_init(dlog_1modpe_t t, ulong a1, ulong p, ulong e);
void dlog_crt_init(dlog_crt_t t, ulong a, ulong mod, ulong n, ulong num);
void dlog_power_init(dlog_power_t t, ulong a, ulong mod, ulong p, ulong e, ulong num);
void dlog_modpe_init(dlog_modpe_t t, ulong a, ulong p, ulong e, ulong pe, ulong num);
void dlog_bsgs_init(dlog_bsgs_t t, ulong a, ulong mod, ulong n, ulong m);
void dlog_rho_init(dlog_rho_t t, ulong a, ulong mod, ulong n);
/*#define dlog_bsgs_init(t, a, n, m) bsgs_table_init(t, a, n, m)*/
void dlog_order23_clear(dlog_order23_t t);
void dlog_table_clear(dlog_table_t t);
void dlog_1modpe_clear(dlog_1modpe_t t);
void dlog_crt_clear(dlog_crt_t t);
@ -175,6 +181,7 @@ void dlog_bsgs_clear(dlog_bsgs_t t);
void dlog_rho_clear(dlog_rho_t t);
/*#define dlog_bsgs_clear(t) bsgs_table_clear(t)*/
ulong dlog_order23(const dlog_order23_t t, ulong b);
ulong dlog_table(const dlog_table_t t, ulong b);
ulong dlog_crt(const dlog_crt_t t, ulong b);
ulong dlog_power(const dlog_power_t t, ulong b);
@ -198,6 +205,9 @@ typedef struct
} log_pair_t;
void dlog_vec_loop(ulong * v, ulong nv, ulong a, ulong va, nmod_t mod, ulong na, nmod_t order);
void dlog_vec_eratos_ph(ulong *v, ulong nv, ulong a, ulong va, ulong M, nmod_t mod, ulong na, nmod_t order);
void dlog_vec_eratos(ulong *v, ulong nv, ulong a, ulong va, nmod_t mod, ulong na, nmod_t order);
void dlog_vec_sieve_ph(ulong *v, ulong nv, ulong a, ulong va, ulong M, nmod_t mod, ulong na, nmod_t order);
void dlog_vec_sieve(ulong *v, ulong nv, ulong a, ulong va, nmod_t mod, ulong na, nmod_t order);
void dlog_vec_crt(ulong *v, ulong nv, ulong a, ulong va, nmod_t mod, ulong na, nmod_t order);
void dlog_vec(ulong *v, ulong nv, ulong a, ulong va, nmod_t mod, ulong na, nmod_t order);

View file

@ -33,7 +33,7 @@ dlog_bsgs(const dlog_bsgs_t t, ulong b)
apow_t c, * x;
c.ak = b;
for (i = 0; i <= t->g; i++)
for (i = 0; i < t->g; i++)
{
x = bsearch(&c, t->table, t->m, sizeof(apow_t),
(int(*)(const void*,const void*))apow_cmp);
@ -42,7 +42,7 @@ dlog_bsgs(const dlog_bsgs_t t, ulong b)
c.ak = nmod_mul(c.ak, t->am, t->mod);
}
flint_printf("Exception (n_discrete_log_bsgs). discrete log not found.\n");
flint_printf(" table size %wu, cosize %wu mod %wu. %wu not found\n",
t->m, t->g, t->mod.n, b);
flint_printf(" table size %wu, cosize %wu mod %wu. %wu not found (a^-m=%wu)\n",
t->m, t->g, t->mod.n, b, t->am);
abort();
}

View file

@ -34,16 +34,16 @@ apow_cmp(const apow_t * x, const apow_t * y)
}
/* set size of table m=sqrt(nk) to compute k logs in a group of size n */
void
ulong
dlog_bsgs_init(dlog_bsgs_t t, ulong a, ulong mod, ulong n, ulong m)
{
ulong k, ak;
if (m >= n) m = n + 1;
t->table = (apow_t *)flint_malloc(m * sizeof(apow_t));
if (m > n) m = n;
nmod_init(&t->mod, mod);
t->m = m;
t->g = n / m;
t->g = n / m + 1;
for (k = 0, ak = 1; k < m; k++)
{
@ -54,6 +54,7 @@ dlog_bsgs_init(dlog_bsgs_t t, ulong a, ulong mod, ulong n, ulong m)
t->am = nmod_inv(ak, t->mod);
qsort(t->table, m, sizeof(apow_t), (int(*)(const void*,const void*))apow_cmp);
return t->g;
}
void

View file

@ -25,12 +25,13 @@
#include "dlog.h"
void
ulong
dlog_crt_init(dlog_crt_t t, ulong a, ulong mod, ulong n, ulong num)
{
int k;
n_factor_t fac;
ulong * M, * u;
ulong cost = 0;
n_factor_init(&fac);
n_factor(&fac, n, 1);
@ -54,8 +55,17 @@ dlog_crt_init(dlog_crt_t t, ulong a, ulong mod, ulong n, ulong num)
M[k] = n / mk;
u[k] = nmod_mul(M[k], n_invmod(M[k] % mk, mk), t->n);
/* depends on the power */
#if 0
flint_printf("[sub-crt -- init for size %wu mod %wu]\n", mk, mod);
#endif
dlog_precomp_pe_init(t->pre[k], nmod_pow_ui(a, M[k], t->mod), mod, p, e, mk, num);
cost += t->pre[k]->cost;
}
#if 0
if (cost > 500)
flint_printf("[crt init for size %wu mod %wu -> cost %wu]\n", n,mod,cost);
#endif
return cost;
}
void

View file

@ -26,7 +26,7 @@
#include "dlog.h"
#include "padic.h"
void
ulong
dlog_modpe_init(dlog_modpe_t t, ulong a, ulong p, ulong e, ulong pe, ulong num)
{
t->p = p;
@ -34,6 +34,7 @@ dlog_modpe_init(dlog_modpe_t t, ulong a, ulong p, ulong e, ulong pe, ulong num)
t->pe = pe;
dlog_precomp_n_init(t->modp, a, p, p-1, num);
dlog_1modpe_init(t->modpe, n_powmod(a, p - 1, pe), p, e);
return t->modp->cost + e;
}
void

32
dlog/order23.c Normal file
View file

@ -0,0 +1,32 @@
/*=============================================================================
This file is part of ARB.
ARB is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
ARB is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with ARB; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2016 Pascal Molin
******************************************************************************/
#include "dlog.h"
ulong
dlog_order23(const dlog_order23_t t, ulong b)
{
return (b == *t) ? 1 : (b == 1) ? 0 : 2;
}

39
dlog/order23_init.c Normal file
View file

@ -0,0 +1,39 @@
/*=============================================================================
This file is part of ARB.
ARB is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
ARB is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with ARB; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2016 Pascal Molin
******************************************************************************/
#include "dlog.h"
ulong
dlog_order23_init(dlog_order23_t t, ulong a)
{
* t = a;
return 0;
}
void
dlog_order23_clear(dlog_order23_t t)
{
return;
}

View file

@ -25,7 +25,7 @@
#include "dlog.h"
void
ulong
dlog_power_init(dlog_power_t t, ulong a, ulong mod, ulong p, ulong e, ulong num)
{
int k;
@ -40,7 +40,8 @@ dlog_power_init(dlog_power_t t, ulong a, ulong mod, ulong p, ulong e, ulong num)
for (k = 1; k < e; k++)
t->apk[k] = nmod_pow_ui(t->apk[k-1], p, t->mod);
dlog_precomp_p_init(t->pre, nmod_inv(t->apk[e-1], t->mod), mod, p, num);
dlog_precomp_p_init(t->pre, nmod_inv(t->apk[e-1], t->mod), mod, p, e * num);
return e * t->pre->cost;
}
void

View file

@ -47,6 +47,9 @@ dlog_precomp(const dlog_precomp_t pre, ulong b)
case DLOG_BSGS:
return dlog_bsgs(pre->t.bsgs, b);
break;
case DLOG_23:
return dlog_order23(pre->t.order23, b);
break;
default:
abort();
break;

View file

@ -26,30 +26,56 @@
#include "math.h"
#include "dlog.h"
#define SMALL_LIM 50
#define TABLE_LIM 50
#define TABLE_P_LIM 50
#define TABLE_MODPE_LIM 50
#define TABLE_PE_LIM 50
#define TABLE_N_LIM 50
#define BSGS_LIM 500
void
dlog_precomp_small_init(dlog_precomp_t pre, ulong a, ulong mod, ulong n, ulong num)
{
if (n <= 3)
{
pre->type = DLOG_23;
pre->cost = dlog_order23_init(pre->t.order23, a);
}
else
{
if ( mod < TABLE_LIM )
{
pre->type = DLOG_TABLE;
pre->cost = dlog_table_init(pre->t.table, a, mod);
}
else
{
pre->type = DLOG_BSGS;
pre->cost = dlog_bsgs_init(pre->t.bsgs, a, mod, n, n);
}
}
}
/* log mod p^e */
void
dlog_precomp_modpe_init(dlog_precomp_t pre, ulong a, ulong p, ulong e, ulong pe, ulong num)
{
if ( pe < TABLE_PE_LIM )
if ( pe < TABLE_MODPE_LIM )
{
pre->type = DLOG_TABLE;
dlog_table_init(pre->t.table, a, pe);
dlog_precomp_small_init(pre, a, pe, pe - pe / p, num);
return;
}
if (e > 1)
{
pre->type = DLOG_MODPE;
dlog_modpe_init(pre->t.modpe, a, p, e, pe, num);
}
else
{
dlog_precomp_n_init(pre, a, p, p - 1, num);
else {
if (e > 1)
{
pre->type = DLOG_MODPE;
pre->cost = dlog_modpe_init(pre->t.modpe, a, p, e, pe, num);
}
else
{
dlog_precomp_n_init(pre, a, p, p - 1, num);
}
}
}
@ -60,20 +86,21 @@ dlog_precomp_n_init(dlog_precomp_t pre, ulong a, ulong mod, ulong n, ulong num)
if (n%2 && n_is_probabprime(n))
dlog_precomp_p_init(pre, a, mod, n, num);
else {
if ( mod < TABLE_N_LIM )
if (n < TABLE_N_LIM)
{
dlog_precomp_small_init(pre, a, mod, n, num);
}
else
{
pre->type = DLOG_TABLE;
dlog_table_init(pre->t.table, a, mod);
} else {
if (n < BSGS_LIM)
{
ulong m;
m = (2 * num < n) ? ceil(sqrt((double) n * num)) : n;
pre->type = DLOG_BSGS;
dlog_bsgs_init(pre->t.bsgs, a, mod, n, m);
pre->cost = dlog_bsgs_init(pre->t.bsgs, a, mod, n, m);
} else {
pre->type = DLOG_CRT;
dlog_crt_init(pre->t.crt, a, mod, n, num);
pre->cost = dlog_crt_init(pre->t.crt, a, mod, n, num);
}
}
}
@ -85,15 +112,14 @@ dlog_precomp_p_init(dlog_precomp_t pre, ulong a, ulong mod, ulong p, ulong num)
{
if ( p < TABLE_P_LIM )
{
pre->type = DLOG_TABLE;
dlog_table_init(pre->t.table, a, mod);
dlog_precomp_small_init(pre, a, mod, p, num);
}
else
{
ulong m;
m = (2 * num < p) ? ceil(sqrt((double) p * num)) : p;
pre->type = DLOG_BSGS;
dlog_bsgs_init(pre->t.bsgs, a, mod, p, m);
pre->cost = dlog_bsgs_init(pre->t.bsgs, a, mod, p, m);
}
}
@ -102,8 +128,7 @@ dlog_precomp_pe_init(dlog_precomp_t pre, ulong a, ulong mod, ulong p, ulong e, u
{
if ( pe < TABLE_PE_LIM )
{
pre->type = DLOG_TABLE;
dlog_table_init(pre->t.table, a, mod);
dlog_precomp_small_init(pre, a, mod, pe, num);
}
else
{
@ -114,7 +139,7 @@ dlog_precomp_pe_init(dlog_precomp_t pre, ulong a, ulong mod, ulong p, ulong e, u
else
{
pre->type = DLOG_POWER;
dlog_power_init(pre->t.power, a, mod, p, e, num);
pre->cost = dlog_power_init(pre->t.power, a, mod, p, e, num);
}
}
}
@ -139,6 +164,9 @@ dlog_precomp_clear(dlog_precomp_t pre)
case DLOG_BSGS:
dlog_bsgs_clear(pre->t.bsgs);
break;
case DLOG_23:
dlog_order23_clear(pre->t.order23);
break;
default:
abort();
break;

View file

@ -27,7 +27,10 @@
#include "profiler.h"
#include <math.h>
typedef void (*multilog_f) (ulong p, ulong a, ulong num);
#define NUMPRIMES 400
#define CSV 0
typedef void (*log_f) (ulong p, ulong a, ulong num);
void
flog_table(ulong p, ulong a, ulong num)
@ -37,7 +40,7 @@ flog_table(ulong p, ulong a, ulong num)
dlog_table_init(t, a, p);
for (k = 1; k < num; k++)
{
if (k == p) continue;
if (k % p == 0) continue;
dlog_table(t, k % p);
}
dlog_table_clear(t);
@ -50,7 +53,7 @@ flog_bsgs(ulong p, ulong a, ulong num)
dlog_bsgs_init(t, a, p, p-1, ceil( sqrt((double)num * p)));
for (k = 1; k < num; k++)
{
if (k == p) continue;
if (k % p == 0) continue;
dlog_bsgs(t, k % p);
}
dlog_bsgs_clear(t);
@ -63,7 +66,7 @@ flog_rho(ulong p, ulong a, ulong num)
dlog_rho_init(t, a, p, p-1);
for (k = 1; k < num; k++)
{
if (k == p) continue;
if (k % p == 0) continue;
dlog_rho(t, k % p);
}
dlog_rho_clear(t);
@ -76,7 +79,7 @@ flog_crt(ulong p, ulong a, ulong num)
dlog_crt_init(t, a, p, p-1, num);
for (k = 1; k < num; k++)
{
if (k == p) continue;
if (k % p == 0) continue;
dlog_crt(t, k % p);
}
dlog_crt_clear(t);
@ -89,37 +92,38 @@ flog_gen(ulong p, ulong a, ulong num)
dlog_precomp_n_init(t, a, p, p-1, num);
for (k = 1; k < num; k++)
{
if (k == p) continue;
if (k % p == 0) continue;
dlog_precomp(t, k % p);
}
dlog_precomp_clear(t);
}
void
dlog_bench(multilog_f flog, const ulong * p, const ulong * a, int np, int num)
{
int i;
ulong q;
TIMEIT_ONCE_START
for (i = 0; i < np; i ++)
flog(p[i], a[i], num);
TIMEIT_ONCE_STOP
}
int main()
{
slong iter, k, nv, nref, r, nr;
ulong minq, maxq;
ulong * rand;
int nbits, nl = 4;
int vl[5] = { 1, 10, 100, 1000 , 5000};
int nbits, nl = 5;
int l[5] = { 1, 10, 100, 1000 , 5000};
int nf = 4;
log_f func[4] = { flog_table, flog_bsgs, flog_crt, flog_gen };
char * n[4] = { "table", "bsgs", "crt", "generic" };
int np = NUMPRIMES;
flint_rand_t state;
flint_randinit(state);
for (nbits = 10; nbits < 52; nbits += 10)
for (nbits = 10; nbits < 50; nbits += 5)
{
int i, np = 100;
ulong p[100], a[100];
int i;
ulong p[NUMPRIMES], a[NUMPRIMES];
if (nbits >= 25)
np /= 2;
for (i=0; i < np; i++)
{
p[i] = n_randprime(state, nbits, 0);
@ -128,36 +132,33 @@ int main()
for (i = 0; i < nl; i++)
{
flint_printf("%wu * logs mod primes of size %wu.....\n", vl[i], nbits);
int f;
#if LOG
flint_printf("%d * logs mod primes of size %d.....\n", l[i], nbits);
#endif
if (nbits <= 20)
{
flint_printf("table.......... ");
fflush(stdout);
dlog_bench(flog_table, p, a, np, vl[i]);
}
if (nbits <= 40 || vl[i] <= 10)
for (f = 0; f < nf; f++)
{
flint_printf("bsgs........... ");
int j;
/* skip useless */
if (f == 0 && nbits >= 20)
continue;
if (f == 1 && nbits >= 30 && l[i] > 10)
continue;
#if LOG
flint_printf("%-20s... ",n[f]);
fflush(stdout);
dlog_bench(flog_bsgs, p, a, np, vl[i]);
#endif
TIMEIT_ONCE_START
for (j = 0; j < np; j ++)
(func[f])(p[j], a[j], l[i]);
#if LOG == 0
flint_printf("%-8s, %2d, %4d, %3d, ",n[f],nbits,l[i],np);
#endif
TIMEIT_ONCE_STOP
}
if (nbits <= 20 || vl[i] == 1)
{
flint_printf("rho............ ");
fflush(stdout);
dlog_bench(flog_rho, p, a, np, vl[i]);
}
flint_printf("crt............ ");
fflush(stdout);
dlog_bench(flog_crt, p, a, np, vl[i]);
flint_printf("generic........ ");
fflush(stdout);
dlog_bench(flog_gen, p, a, np, vl[i]);
}
}
flint_randclear(state);

View file

@ -26,7 +26,7 @@
#include "dlog.h"
/* assume mod is small so no overflow */
void
ulong
dlog_table_init(dlog_table_t t, ulong a, ulong mod)
{
int k;
@ -41,6 +41,7 @@ dlog_table_init(dlog_table_t t, ulong a, ulong mod)
ak = (ak * a) % mod;
}
while (ak != 1);
return 1;
}
void