[u/mdw/catacomb] / prim.c

/* -*-c-*-
 *
 * $Id: prim.c,v 1.4 2004/04/08 01:36:15 mdw Exp $
 *
 * Finding primitive elements
 *
 * (c) 1999 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of Catacomb.
 *
 * Catacomb is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * Catacomb 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 Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with Catacomb; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Header files ------------------------------------------------------*/

#include "mp.h"
#include "mpint.h"
#include "mpmont.h"
#include "mprand.h"
#include "pgen.h"
#include "prim.h"

/*----- Main code ---------------------------------------------------------*/

/* --- @prim_test@ --- */

int prim_test(int rq, pgen_event *ev, void *p)
{
  prim_ctx *c = p;
  int rc = rq;

  switch (rq) {
    case PGEN_BEGIN:
      return (PGEN_TRY);
    case PGEN_TRY: {
      mp *x;
      rc = PGEN_FAIL;

      if (!c->exp)
	x = mp_copy(ev->m);
      else {
	x = mpmont_exp(&c->mm, MP_NEW, ev->m, c->exp);
	if (MP_EQ(x, MP_ONE))
	  goto done;
      }
      if (c->n == 0)
	goto ok;
      else {
	size_t n = c->n;
	mp **f = c->f;
	mp *y = MP_NEW;
	while (n) {
	  y = mpmont_exp(&c->mm, y, x, *f);
	  if (MP_EQ(y, MP_ONE)) {
	    mp_drop(y);
	    goto done;
	  }
	  n--; f++;
	}
	mp_drop(y);
      }
    ok:
      rc = PGEN_DONE;
      mp_drop(ev->m);
      ev->m = x;
      break;
    done:
      mp_drop(x);
    } break;
  }

  return (rc);
}

/* --- Trivial stepping functions -----------------------------------------*/

/* --- @prim_step@ --- */

int prim_step(int rq, pgen_event *ev, void *p)
{
  unsigned *i = p;
  switch (rq) {
    case PGEN_BEGIN:
    case PGEN_TRY:
      if (*i >= NPRIME)
	return PGEN_FAIL;
      ev->m = mp_fromint(ev->m, primetab[(*i)++]);
      return (PGEN_TRY);
  }
  return (0);
}

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
fcdaa180	1	/* --c--
fcdaa180	2	*
b817bfc6	3	* $Id: prim.c,v 1.4 2004/04/08 01:36:15 mdw Exp $
fcdaa180	4	*
	5	* Finding primitive elements
	6	*
	7	* (c) 1999 Straylight/Edgeware
	8	*/
	9
45c0fd36	10	/----- Licensing notice --------------------------------------------------
fcdaa180	11	*
	12	* This file is part of Catacomb.
	13	*
	14	* Catacomb is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU Library General Public License as
	16	* published by the Free Software Foundation; either version 2 of the
	17	* License, or (at your option) any later version.
45c0fd36	18	*
fcdaa180	19	* Catacomb is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU Library General Public License for more details.
45c0fd36	23	*
fcdaa180	24	* You should have received a copy of the GNU Library General Public
	25	* License along with Catacomb; if not, write to the Free
	26	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
	27	* MA 02111-1307, USA.
	28	*/
	29
fcdaa180	30	/----- Header files ------------------------------------------------------/
	31
	32	#include "mp.h"
	33	#include "mpint.h"
	34	#include "mpmont.h"
	35	#include "mprand.h"
	36	#include "pgen.h"
	37	#include "prim.h"
	38
	39	/----- Main code ---------------------------------------------------------/
	40
	41	/* --- @prim_test@ --- */
	42
	43	int prim_test(int rq, pgen_event ev, void p)
	44	{
	45	prim_ctx *c = p;
	46	int rc = rq;
	47
	48	switch (rq) {
	49	case PGEN_BEGIN:
	50	return (PGEN_TRY);
	51	case PGEN_TRY: {
6f80d39f	52	mp *x;
fcdaa180	53	rc = PGEN_FAIL;
fcdaa180	54
6f80d39f	55	if (!c->exp)
45c0fd36	56	x = mp_copy(ev->m);
6f80d39f	57	else {
6f80d39f	58	x = mpmont_exp(&c->mm, MP_NEW, ev->m, c->exp);
22bab86c	59	if (MP_EQ(x, MP_ONE))
6f80d39f	60	goto done;
	61	}
	62	if (c->n == 0)
45c0fd36	63	goto ok;
6f80d39f	64	else {
	65	size_t n = c->n;
	66	mp **f = c->f;
	67	mp *y = MP_NEW;
fcdaa180	68	while (n) {
6f80d39f	69	y = mpmont_exp(&c->mm, y, x, *f);
22bab86c	70	if (MP_EQ(y, MP_ONE)) {
6f80d39f	71	mp_drop(y);
fcdaa180	72	goto done;
6f80d39f	73	}
fcdaa180	74	n--; f++;
fcdaa180	75	}
6f80d39f	76	mp_drop(y);
fcdaa180	77	}
6f80d39f	78	ok:
fcdaa180	79	rc = PGEN_DONE;
6f80d39f	80	mp_drop(ev->m);
	81	ev->m = x;
	82	break;
fcdaa180	83	done:
	84	mp_drop(x);
	85	} break;
	86	}
	87
	88	return (rc);
	89	}
	90
	91	/* --- Trivial stepping functions -----------------------------------------*/
	92
	93	/* --- @prim_step@ --- */
	94
	95	int prim_step(int rq, pgen_event ev, void p)
	96	{
	97	unsigned *i = p;
	98	switch (rq) {
	99	case PGEN_BEGIN:
	100	case PGEN_TRY:
	101	if (*i >= NPRIME)
	102	return PGEN_FAIL;
	103	ev->m = mp_fromint(ev->m, primetab[(*i)++]);
	104	return (PGEN_TRY);
	105	}
	106	return (0);
	107	}
	108
	109	/----- That's all, folks -------------------------------------------------/