Rearrange the file tree.

[u/mdw/catacomb] / mprand.c

diff --git a/mprand.c b/mprand.c
deleted file mode 100644 (file)
index c0f9675..0000000
--- a/mprand.c
+++ /dev/null
@@ -1,140 +0,0 @@
-/* -*-c-*-
- *
- * $Id: mprand.c,v 1.5 2004/04/08 01:36:15 mdw Exp $
- *
- * Generate a random multiprecision integer
- *
- * (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 <mLib/alloc.h>
-
-#include "grand.h"
-#include "mp.h"
-#include "mprand.h"
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @mprand@ --- *
- *
- * Arguments:  @mp *d@ = destination integer
- *             @unsigned b@ = number of bits
- *             @grand *r@ = pointer to random number source
- *             @mpw or@ = mask to OR with low-order bits
- *
- * Returns:    A random integer with the requested number of bits.
- *
- * Use:                Constructs an arbitrarily large pseudorandom integer.
- *             Assuming that the generator @r@ is good, the result is
- *             uniformly distributed in the interval %$[2^{b - 1}, 2^b)$%.
- *             The result is then ORred with the given @or@ value.  This
- *             will often be 1, to make the result odd.
- */
-
-mp *mprand(mp *d, unsigned b, grand *r, mpw or)
-{
-  size_t sz = (b + 7) >> 3;
-  arena *a = (d && (d->f & MP_BURN)) ? arena_secure : arena_global;
-  octet *v = x_alloc(a, sz);
-  unsigned m;
-
-  /* --- Fill buffer with random data --- */
-
-  r->ops->fill(r, v, sz);
-
-  /* --- Force into the correct range --- *
-   *
-   * This is slightly tricky.  Oh, well.
-   */
-
-  b = (b - 1) & 7;
-  m = (1 << b);
-  v[0] = (v[0] & (m - 1)) | m;
-
-  /* --- Mask, load and return --- */
-
-  d = mp_loadb(d, v, sz);
-  d->v[0] |= or;
-  memset(v, 0, sz);
-  x_free(a, v);
-  return (d);
-}
-
-/* --- @mprand_range@ --- *
- *
- * Arguments:  @mp *d@ = destination integer
- *             @mp *l@ = limit for random number
- *             @grand *r@ = random number source
- *             @mpw or@ = mask for low-order bits
- *
- * Returns:    A pseudorandom integer, unformly distributed over the
- *             interval %$[0, l)$%.
- *
- * Use:                Generates a uniformly-distributed pseudorandom number in the
- *             appropriate range.
- */
-
-mp *mprand_range(mp *d, mp *l, grand *r, mpw or)
-{
-  size_t b = mp_bits(l);
-  size_t sz = (b + 7) >> 3;
-  arena *a = (d && (d->f & MP_BURN)) ? arena_secure : arena_global;
-  octet *v = x_alloc(a, sz);
-  unsigned m;
-
-  /* --- The algorithm --- *
-   *
-   * Rather simpler than most.  Find the number of bits in the number %$l$%
-   * (i.e., the integer %$b$% such that %$2^{b - 1} \le l < 2^b$%), and
-   * generate pseudorandom integers with %$n$% bits (but not, unlike in the
-   * function above, with the top bit forced to 1).  If the integer is
-   * greater than or equal to %$l$%, try again.
-   *
-   * This is similar to the algorithms used in @lcrand_range@ and friends,
-   * except that I've forced the `raw' range of the random numbers such that
-   * %$l$% itself is the largest multiple of %$l$% in the range (since, by
-   * the inequality above, %$2^b \le 2l$%).  This removes the need for costly
-   * division and remainder operations.
-   *
-   * As usual, the number of iterations expected is two.
-   */
-
-  b = ((b - 1) & 7) + 1;
-  m = (1 << b) - 1;
-  do {
-    r->ops->fill(r, v, sz);
-    v[0] &= m;
-    d = mp_loadb(d, v, sz);
-    d->v[0] |= or;
-  } while (MP_CMP(d, >=, l));
-
-  /* --- Done --- */
-
-  memset(v, 0, sz);
-  x_free(a, v);
-  return (d);
-}
-
-/*----- That's all, folks -------------------------------------------------*/