way.
* sn-oddevenmerge
- Creates a odd-even-merge-sort network with a given number of inputs and
+ Create an odd-even merge network with a given number of left and right
+ inputs. The resulting network is printed to STDOUT.
+
+ * sn-oddevensort
+ Creates an odd-even mergesort network with a given number of inputs and
prints the network to STDOUT.
+ * sn-pairwise
+ Create a pairwise sorting network based on the paper by Ian Parberry.
+
* sn-shmoo
Prints a so-called "shmoo chart" of a comparator network to STDOUT. The
running time of this tool is exponential, roughly O(m * 2^n) where m is the
bin_PROGRAMS = sn-apply sn-batcher sn-bb sn-bb-merge sn-check-bf sn-cut \
sn-info sn-markov sn-merge sn-normalize \
- sn-oddevenmerge sn-oddevensort \
+ sn-oddevenmerge sn-oddevensort sn-pairwise \
sn-shmoo sn-show sn-svg sn-tex
libsortnetwork_la_SOURCES = sn_network.c sn_network.h \
sn_oddevensort_SOURCES = sn-oddevensort.c
sn_oddevensort_LDADD = libsortnetwork.la
+sn_pairwise_SOURCES = sn-pairwise.c
+sn_pairwise_LDADD = libsortnetwork.la
+
sn_shmoo_SOURCES = sn-shmoo.c
sn_shmoo_LDADD = libsortnetwork.la
--- /dev/null
+/**
+ * libsortnetwork - src/sn-pairwise.c
+ * Copyright (C) 2008-2010 Florian octo Forster
+ *
+ * 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; only version 2 of the License is applicable.
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors:
+ * Florian octo Forster <ff at octo.it>
+ **/
+
+#ifndef _ISOC99_SOURCE
+# define _ISOC99_SOURCE
+#endif
+#ifndef _POSIX_C_SOURCE
+# define _POSIX_C_SOURCE 200112L
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "sn_network.h"
+
+int main (int argc, char **argv)
+{
+ sn_network_t *n;
+ size_t inputs_num;
+
+ if (argc != 2)
+ {
+ printf ("Usage: %s <num inputs>\n", argv[0]);
+ return (0);
+ }
+
+ inputs_num = (size_t) atoi (argv[1]);
+ if (inputs_num < 2)
+ {
+ fprintf (stderr, "Invalid number of inputs: %zu\n", inputs_num);
+ return (1);
+ }
+
+ n = sn_network_create_pairwise (inputs_num);
+ if (n == NULL)
+ {
+ printf ("n == NULL!\n");
+ return (1);
+ }
+
+ sn_network_write (n, stdout);
+
+ return (0);
+} /* int main */
+
+/* vim: set shiftwidth=2 softtabstop=2 : */
}
} /* }}} sn_network_t *sn_network_create_odd_even_mergesort */
+static int sn_network_create_pairwise_internal (sn_network_t *n, /* {{{ */
+ int *inputs, int inputs_num)
+{
+ int i;
+ int inputs_copy[inputs_num];
+ int m;
+
+ for (i = 1; i < inputs_num; i += 2)
+ {
+ sn_comparator_t *c = sn_comparator_create (inputs[i-1], inputs[i]);
+ sn_network_comparator_add (n, c);
+ sn_comparator_destroy (c);
+ }
+
+ if (inputs_num <= 2)
+ return (0);
+
+ /* Sort "pairs" recursively. Like with odd-even mergesort, odd and even lines
+ * are handled recursively and later reunited. */
+ for (i = 0; i < inputs_num; i += 2)
+ inputs_copy[(int) (i / 2)] = inputs[i];
+ /* Recursive call #1 with first set of lines */
+ sn_network_create_pairwise_internal (n, inputs_copy,
+ (int) ((inputs_num + 1) / 2));
+
+ for (i = 1; i < inputs_num; i += 2)
+ inputs_copy[(int) (i / 2)] = inputs[i];
+ /* Recursive call #2 with second set of lines */
+ sn_network_create_pairwise_internal (n, inputs_copy,
+ (int) (inputs_num/ 2));
+
+ /* m is the "amplitude" of the sorted pairs. This is a bit tricky to read due
+ * to different indices being used in the paper, unfortunately. */
+ m = inputs_num / 2;
+ while (m > 1)
+ {
+ for (i = 1; (i + (m - 1)) < inputs_num; i += 2)
+ {
+ int left = i;
+ int right = i + (m - 1);
+ sn_comparator_t *c;
+
+ assert (left < right);
+ c = sn_comparator_create (inputs[left], inputs[right]);
+ sn_network_comparator_add (n, c);
+ sn_comparator_destroy (c);
+ }
+
+ m = m / 2;
+ } /* while (m > 1) */
+
+ return (0);
+} /* }}} int sn_network_create_pairwise_internal */
+
+sn_network_t *sn_network_create_pairwise (int inputs_num) /* {{{ */
+{
+ sn_network_t *n = sn_network_create (inputs_num);
+ int inputs[inputs_num];
+ int i;
+
+ if (n == NULL)
+ return (NULL);
+
+ for (i = 0; i < inputs_num; i++)
+ inputs[i] = i;
+
+ sn_network_create_pairwise_internal (n, inputs, inputs_num);
+ sn_network_compress (n);
+
+ return (n);
+} /* }}} sn_network_t *sn_network_create_pairwise */
+
int sn_network_stage_add (sn_network_t *n, sn_stage_t *s) /* {{{ */
{
sn_stage_t **temp;
sn_network_t *sn_network_create_odd_even_mergesort (int inputs_num);
/**
+ * Creates a new sorting network using the Pairwise sorting algorithm published
+ * by Ian Parberry.
+ * \param inputs_num Number of inputs / outputs of the sorting network.
+ * \return A pointer to the newly allocated sorting network or \c NULL if an
+ * invalid number of inputs was given or allocation failed.
+ */
+sn_network_t *sn_network_create_pairwise (int inputs_num);
+
+/**
* Append a new stage to a comparator network.
*
* \param n The comparator network to which to add the stage.
projects / sort-networks.git / commitdiff