X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fadt%2Fbipartite.c;h=cc627286012b04a7fe1097bebb7e7712ecb603ca;hb=a999e1baedb84dc9b83059708699dac1c7fdb9a2;hp=c781a9917b6a3e590e5ffe0ba13cddcfd517db01;hpb=1bfc88e0b316097777f7d54ce55b0833f922f844;p=libfirm

diff --git a/ir/adt/bipartite.c b/ir/adt/bipartite.c
index c781a9917..cc6272860 100644
--- a/ir/adt/bipartite.c
+++ b/ir/adt/bipartite.c
@@ -1,24 +1,55 @@
+/*
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @brief  Specialized implementation for perfect bipartite matching.
+ * @author Sebastian Hack
+ * @cvs-id $Id$
+ */
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 
 #include <stdio.h>
 #include <assert.h>
 
 #include "bitset.h"
 #include "bipartite.h"
+#include "xmalloc.h"
 
 struct _bipartite_t {
 	int n_left, n_right;
-	bitset_t **adj;
+	bitset_t *adj[1];
 };
 
 bipartite_t *bipartite_new(int n_left, int n_right)
 {
-	int i;
-	bipartite_t *gr = malloc(sizeof(*gr));
+	int i, size;
+	bipartite_t *gr;
+
+	size = n_left > 0 ? n_left - 1 : 0;
+	gr = xmalloc(sizeof(*gr) + size * sizeof(void *));
 	memset(gr, 0, sizeof(*gr));
 
 	gr->n_left = n_left;
 	gr->n_right = n_right;
-	gr->adj = malloc(n_left * sizeof(void *));
 
 	for(i = 0; i < n_left; ++i)
 		gr->adj[i] = bitset_malloc(n_right);
@@ -31,8 +62,6 @@ void bipartite_free(bipartite_t *gr)
 	int i;
 	for(i = 0; i < gr->n_left; ++i)
 		bitset_free(gr->adj[i]);
-
-	free(gr->adj);
 	free(gr);
 }
 
@@ -59,7 +88,7 @@ static int apply_alternating_path(const bipartite_t *gr, int *matching,
 {
 	int left, right;
 	int done_something = 0;
-	bitset_t *tmp = bitset_malloc(gr->n_left);
+	bitset_t *tmp = bitset_alloca(gr->n_right);
 
 	for(left = 0; left < gr->n_left; ++left) {
 		bitset_t *left_adj = gr->adj[left];
@@ -80,10 +109,12 @@ static int apply_alternating_path(const bipartite_t *gr, int *matching,
 
 			assert(right != -1);
 
-			/* We have to find another left node which has the old right
-			 * one as a neighbor. */
+			/*
+				We have to find another left node which has the old right one as a neighbor.
+				This node must not be part of a matching
+			*/
 			for(i = 0; i < gr->n_left; ++i)
-				if(i != left && bitset_is_set(gr->adj[i], old_right))
+				if(i != left && bitset_is_set(gr->adj[i], old_right) && !bitset_is_set(matched_left, i))
 					break;
 
 			/* If no such node can be found, exit. */
@@ -107,7 +138,7 @@ static int apply_alternating_path(const bipartite_t *gr, int *matching,
 			if(bitset_popcnt(tmp) == 0)
 				continue;
 
-			right = bitset_min(tmp);
+			right = bitset_next_set(tmp, 0);
 			assert(!bitset_is_set(matched_right, right));
 			matching[left] = right;
 			bitset_set(matched_left, left);
@@ -116,29 +147,34 @@ static int apply_alternating_path(const bipartite_t *gr, int *matching,
 		}
 	}
 
-	bitset_free(tmp);
-
 	return done_something;
 }
 
 void bipartite_matching(const bipartite_t *gr, int *matching)
 {
-	bitset_t *matched_left = bitset_malloc(gr->n_left);
-	bitset_t *matched_right = bitset_malloc(gr->n_right);
+	bitset_t *matched_left = bitset_alloca(gr->n_left);
+	bitset_t *matched_right = bitset_alloca(gr->n_right);
 
 	memset(matching, -1, gr->n_left * sizeof(int));
 	while(apply_alternating_path(gr, matching, matched_left, matched_right));
-
-	bitset_free(matched_left);
-	bitset_free(matched_right);
 }
 
-void bipartite_dump(FILE *f, const bipartite_t *gr)
+void bipartite_dump_f(FILE *f, const bipartite_t *gr)
 {
 	int i;
 
 	for(i = 0; i < gr->n_left; ++i) {
+		fprintf(f, "%d: ", i);
 		bitset_fprint(f, gr->adj[i]);
 		fprintf(f, "\n");
 	}
 }
+
+void bipartite_dump(const char *name, const bipartite_t *gr) {
+	FILE *f = fopen(name, "w");
+
+	if (f) {
+		bipartite_dump_f(f, gr);
+		fclose(f);
+	}
+}