New multiprecision integer arithmetic suite.

[u/mdw/catacomb] / mp-mem.c

/* -*-c-*-
 *
 * $Id: mp-mem.c,v 1.1 1999/11/17 18:02:16 mdw Exp $
 *
 * Memory management for multiprecision numbers
 *
 * (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: mp-mem.c,v $
 * Revision 1.1  1999/11/17 18:02:16  mdw
 * New multiprecision integer arithmetic suite.
 *
 */

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

#include "mp.h"

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

/* --- @mp_create@ --- *
 *
 * Arguments:	@size_t sz@ = size of vector required
 *
 * Returns:	Pointer to pristine new MP structure with enough memory
 *		bolted onto it.
 *
 * Use:		Creates a new multiprecision integer, initially zero.  The
 *		integer has a single reference.
 */

mp *mp_create(size_t sz)
{
  mp *m = CREATE(mp);
  m->v = MP_ALLOC(sz);
  m->vl = m->v + sz;
  m->sz = sz;
  m->f = MP_UNDEF;
  m->ref = 1;
  return (m);
}

/* --- @mp_build@ --- *
 *
 * Arguments:	@mp *m@ = pointer to an MP block to fill in
 *		@mpw *v@ = pointer to a word array
 *		@mpw *vl@ = pointer just past end of array
 *
 * Returns:	---
 *
 * Use:		Creates a multiprecision integer representing some smallish
 *		number.  You must provide storage for the number and dispose
 *		of it when you've finished with it.  The number is marked as
 *		constant while it exists.
 */

void mp_build(mp *m, mpw *v, mpw *vl)
{
  m->v = v;
  m->vl = vl;
  m->sz = vl - v;
  m->f = MP_CONST;
  m->ref = 1;
}

/* --- @mp_destroy@ --- *
 *
 * Arguments:	@mp *m@ = pointer to a multiprecision integer
 *
 * Returns:	---
 *
 * Use:		Destroys a multiprecision integer. The reference count isn't
 *		checked.  Don't use this function if you don't know what
 *		you're doing: use @mp_drop@ instead.
 */

void mp_destroy(mp *m)
{
  if (m->f & MP_CONST)
    return;
  if (m->f & MP_BURN)
    memset(m->v, 0, MPWS(m->sz));
  MP_FREE(m->v);
  DESTROY(m);
}

/* --- @mp_copy@ --- *
 *
 * Arguments:	@mp *m@ = pointer to a multiprecision integer
 *
 * Returns:	A copy of the given multiprecision integer.
 *
 * Use:		Copies the given integer.  In fact you just get another
 *		reference to the same old one again.
 */

mp *mp_copy(mp *m) { return MP_COPY(m); }

/* --- @mp_drop@ --- *
 *
 * Arguments:	@mp *m@ = pointer to a multiprecision integer
 *
 * Returns:	---
 *
 * Use:		Drops a reference to an integer which isn't wanted any more.
 *		If there are no more references, the integer is destroyed.
 */

void mp_drop(mp *m) { MP_DROP(m); }

/* --- @mp_split@ --- *
 *
 * Arguments:	@mp *m@ = pointer to a multiprecision integer
 *
 * Returns:	A reference to the same integer, possibly with a different
 *		address.
 *
 * Use:		Splits off a modifiable version of the integer referred to.
 */

mp *mp_split(mp *m) { MP_SPLIT(m); return (m); }

/* --- @mp_resize@ --- *
 *
 * Arguments:	@mp *m@ = pointer to a multiprecision integer
 *		@size_t sz@ = new size
 *
 * Returns:	---
 *
 * Use:		Resizes the vector containing the integer's digits.  The new
 *		size must be at least as large as the current integer's
 *		length.  This isn't really intended for client use.
 */

void mp_resize(mp *m, size_t sz) { MP_RESIZE(m, sz); }

/* --- @mp_ensure@ --- *
 *
 * Arguments:	@mp *m@ = pointer to a multiprecision integer
 *		@size_t sz@ = required size
 *
 * Returns:	---
 *
 * Use:		Ensures that the integer has enough space for @sz@ digits.
 *		The value is not changed.
 */

void mp_ensure(mp *m, size_t sz) { MP_ENSURE(m, sz); }

/* --- @mp_modify@ --- *
 *
 * Arguments:	@mp *m@ = pointer to a multiprecision integer
 *		@size_t sz@ = size required
 *
 * Returns:	Pointer to the integer (possibly different).
 *
 * Use:		Prepares an integer to be overwritten.  It's split off from
 *		other references to the same integer, and sufficient space is
 *		allocated.
 */

mp *mp_modify(mp *m, size_t sz) { MP_MODIFY(m, sz); return (m); }

/*----- That's all, folks -------------------------------------------------*/