--- /dev/null
+/* Family of functions for random integers.
+ Copyright (C) 1995-1997, 2000-2002, 2012 Free Software Foundation, Inc.
+
+ This program 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 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/*
+ * This is derived from the Berkeley source:
+ * @(#)random.c 5.5 (Berkeley) 7/6/88
+ * It was reworked for the GNU C Library by Roland McGrath.
+ * Rewritten to use reentrant functions by Ulrich Drepper, 1995.
+ */
+
+/*
+ Copyright (C) 1983 Regents of the University of California.
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ 1. Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ 4. Neither the name of the University nor the names of its contributors
+ may be used to endorse or promote products derived from this software
+ without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ SUCH DAMAGE.*/
+
+#include <config.h>
+
+/* Specification. */
+#include <stdlib.h>
+
+#include <stdint.h>
+#include <time.h>
+
+/* This file can assume the 'struct random_data' and associated *_r functions
+ from gnulib. */
+
+/* Linear congruential. */
+#define TYPE_0 0
+#define BREAK_0 8
+#define DEG_0 0
+#define SEP_0 0
+
+/* x**7 + x**3 + 1. */
+#define TYPE_1 1
+#define BREAK_1 32
+#define DEG_1 7
+#define SEP_1 3
+
+/* x**15 + x + 1. */
+#define TYPE_2 2
+#define BREAK_2 64
+#define DEG_2 15
+#define SEP_2 1
+
+/* x**31 + x**3 + 1. */
+#define TYPE_3 3
+#define BREAK_3 128
+#define DEG_3 31
+#define SEP_3 3
+
+/* x**63 + x + 1. */
+#define TYPE_4 4
+#define BREAK_4 256
+#define DEG_4 63
+#define SEP_4 1
+
+/* Array versions of the above information to make code run faster.
+ Relies on fact that TYPE_i == i. */
+
+#define MAX_TYPES 5 /* Max number of types above. */
+
+/* Initially, everything is set up as if from:
+ initstate(1, randtbl, 128);
+ Note that this initialization takes advantage of the fact that srandom
+ advances the front and rear pointers 10*rand_deg times, and hence the
+ rear pointer which starts at 0 will also end up at zero; thus the zeroth
+ element of the state information, which contains info about the current
+ position of the rear pointer is just
+ (MAX_TYPES * (rptr - state)) + TYPE_3 == TYPE_3. */
+
+static int32_t randtbl[DEG_3 + 1] =
+ {
+ TYPE_3,
+
+ -1726662223, 379960547, 1735697613, 1040273694, 1313901226,
+ 1627687941, -179304937, -2073333483, 1780058412, -1989503057,
+ -615974602, 344556628, 939512070, -1249116260, 1507946756,
+ -812545463, 154635395, 1388815473, -1926676823, 525320961,
+ -1009028674, 968117788, -123449607, 1284210865, 435012392,
+ -2017506339, -911064859, -370259173, 1132637927, 1398500161,
+ -205601318,
+ };
+
+static struct random_data generator =
+ {
+/* FPTR and RPTR are two pointers into the state info, a front and a rear
+ pointer. These two pointers are always rand_sep places aparts, as they
+ cycle through the state information. (Yes, this does mean we could get
+ away with just one pointer, but the code for random is more efficient
+ this way). The pointers are left positioned as they would be from the call:
+ initstate(1, randtbl, 128);
+ (The position of the rear pointer, rptr, is really 0 (as explained above
+ in the initialization of randtbl) because the state table pointer is set
+ to point to randtbl[1] (as explained below).) */
+
+ /* fptr */ &randtbl[SEP_3 + 1],
+ /* rptr */ &randtbl[1],
+
+/* The following things are the pointer to the state information table,
+ the type of the current generator, the degree of the current polynomial
+ being used, and the separation between the two pointers.
+ Note that for efficiency of random, we remember the first location of
+ the state information, not the zeroth. Hence it is valid to access
+ state[-1], which is used to store the type of the R.N.G.
+ Also, we remember the last location, since this is more efficient than
+ indexing every time to find the address of the last element to see if
+ the front and rear pointers have wrapped. */
+
+ /* state */ &randtbl[1],
+
+ /* rand_type */ TYPE_3,
+ /* rand_deg */ DEG_3,
+ /* rand_sep */ SEP_3,
+
+ /* end_ptr */ &randtbl[sizeof (randtbl) / sizeof (randtbl[0])]
+};
+
+long
+random (void)
+{
+ int32_t val;
+
+ if (random_r (&generator, &val) < 0)
+ abort (); /* should not happen */
+ return val;
+}
+
+void
+srandom (unsigned int seed)
+{
+ (void) srandom_r (seed, &generator); /* may fail! */
+}
+
+char *
+initstate (unsigned int seed, char *buf, size_t buf_size)
+{
+ char *old_state = (char *) ((int32_t *) generator.state - 1);
+ if (initstate_r (seed, buf, buf_size, &generator) < 0)
+ return NULL; /* failed */
+ return old_state;
+}
+
+char *
+setstate (char *arg_state)
+{
+ char *old_state = (char *) ((int32_t *) generator.state - 1);
+ if (setstate_r (arg_state, &generator) < 0)
+ return NULL; /* failed */
+ return old_state;
+}
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