[u/mdw/catacomb] / prim.c

/* -*-c-*-
 *
 * $Id: prim.c,v 1.1 1999/12/22 15:58:59 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.
 */

/*----- Revision history --------------------------------------------------* 
 *
 * $Log: prim.c,v $
 * Revision 1.1  1999/12/22 15:58:59  mdw
 * Search for primitive elements using prime-search equipment.
 *
 */

/*----- 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 = MP_NEW;
      mp *f = c->f;
      rc = PGEN_FAIL;

      x = mpmont_exp(&c->mm, x, ev->m, f);
      if (MP_CMP(x, ==, MP_ONE))
	goto done;
      if (c->n == 0) {
	mp_drop(ev->m);
	ev->m = MP_COPY(x);
      } else {
	size_t n = c->n - 1;
	f++;
	while (n) {
	  x = mpmont_exp(&c->mm, x, ev->m, f);
	  if (MP_CMP(x, ==, MP_ONE))
	    goto done;
	  n--; f++;
	}
      }
      rc = PGEN_DONE;
    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--
	2	*
	3	* $Id: prim.c,v 1.1 1999/12/22 15:58:59 mdw Exp $
	4	*
	5	* Finding primitive elements
	6	*
	7	* (c) 1999 Straylight/Edgeware
	8	*/
	9
	10	/----- Licensing notice --------------------------------------------------
	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.
	18	*
	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.
	23	*
	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
	30	/----- Revision history --------------------------------------------------
	31	*
	32	* $Log: prim.c,v $
	33	* Revision 1.1 1999/12/22 15:58:59 mdw
	34	* Search for primitive elements using prime-search equipment.
	35	*
	36	*/
	37
	38	/----- Header files ------------------------------------------------------/
	39
	40	#include "mp.h"
	41	#include "mpint.h"
	42	#include "mpmont.h"
	43	#include "mprand.h"
	44	#include "pgen.h"
	45	#include "prim.h"
	46
	47	/----- Main code ---------------------------------------------------------/
	48
	49	/* --- @prim_test@ --- */
	50
	51	int prim_test(int rq, pgen_event ev, void p)
	52	{
	53	prim_ctx *c = p;
	54	int rc = rq;
	55
	56	switch (rq) {
	57	case PGEN_BEGIN:
	58	return (PGEN_TRY);
	59	case PGEN_TRY: {
	60	mp *x = MP_NEW;
	61	mp *f = c->f;
	62	rc = PGEN_FAIL;
	63
	64	x = mpmont_exp(&c->mm, x, ev->m, f);
65	if (MP_CMP(x, ==, MP_ONE))
66	goto done;
67	if (c->n == 0) {
68	mp_drop(ev->m);
69	ev->m = MP_COPY(x);
70	} else {
71	size_t n = c->n - 1;
72	f++;
73	while (n) {
74	x = mpmont_exp(&c->mm, x, ev->m, f);
75	if (MP_CMP(x, ==, MP_ONE))
76	goto done;
77	n--; f++;
78	}
79	}
80	rc = PGEN_DONE;
81	done:
82	mp_drop(x);
83	} break;
84	}
85
86	return (rc);
87	}
88
89	/* --- Trivial stepping functions -----------------------------------------*/
90
91	/* --- @prim_step@ --- */
92
93	int prim_step(int rq, pgen_event ev, void p)
94	{
95	unsigned *i = p;
96	switch (rq) {
97	case PGEN_BEGIN:
98	case PGEN_TRY:
99	if (*i >= NPRIME)
100	return PGEN_FAIL;
101	ev->m = mp_fromint(ev->m, primetab[(*i)++]);
102	return (PGEN_TRY);
103	}
104	return (0);
105	}
106
107	/----- That's all, folks -------------------------------------------------/