X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fadt%2Fbipartite.c;h=1ce783a5c7276fb578c359bdcd1edb4d500954e9;hb=d6a6c024a4742e89a95deffaa5e95ca93c9d8c08;hp=199471193233c2a6999cbee6978da310ecfe7a88;hpb=88fa4f38e42ce60750780cae86d35b57a13ce80f;p=libfirm

diff --git a/ir/adt/bipartite.c b/ir/adt/bipartite.c
index 199471193..1ce783a5c 100644
--- a/ir/adt/bipartite.c
+++ b/ir/adt/bipartite.c
@@ -1,3 +1,29 @@
+/*
+ * 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
+ * @version $Id$
+ */
+#include "config.h"
 
 #include <stdio.h>
 #include <assert.h>
@@ -8,20 +34,18 @@
 
 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)
 {
+	bipartite_t *gr = XMALLOCFZ(bipartite_t, adj, n_left);
 	int i;
-	bipartite_t *gr = xmalloc(sizeof(*gr) + n_left * sizeof(void *));
-	memset(gr, 0, sizeof(*gr));
 
 	gr->n_left = n_left;
 	gr->n_right = n_right;
-	gr->adj = (bitset_t**)(gr + 1);
 
-	for(i = 0; i < n_left; ++i)
+	for (i = 0; i < n_left; ++i)
 		gr->adj[i] = bitset_malloc(n_right);
 
 	return gr;
@@ -30,7 +54,7 @@ bipartite_t *bipartite_new(int n_left, int n_right)
 void bipartite_free(bipartite_t *gr)
 {
 	int i;
-	for(i = 0; i < gr->n_left; ++i)
+	for (i = 0; i < gr->n_left; ++i)
 		bitset_free(gr->adj[i]);
 	free(gr);
 }
@@ -60,18 +84,18 @@ static int apply_alternating_path(const bipartite_t *gr, int *matching,
 	int done_something = 0;
 	bitset_t *tmp = bitset_alloca(gr->n_right);
 
-	for(left = 0; left < gr->n_left; ++left) {
+	for (left = 0; left < gr->n_left; ++left) {
 		bitset_t *left_adj = gr->adj[left];
 		int i;
 
 		bitset_copy(tmp, left_adj);
 
-		if(matching[left] >= 0) {
+		if (matching[left] >= 0) {
 			int old_right = matching[left];
 
 			/* Check of all neighbors of the left node are already matched.
 			 * We cannot improve this edge then. */
-			if(bitset_contains(left_adj, matched_right))
+			if (bitset_contains(left_adj, matched_right))
 				continue;
 
 			bitset_andnot(tmp, matched_right);
@@ -79,14 +103,16 @@ 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. */
-			for(i = 0; i < gr->n_left; ++i)
-				if(i != left && bitset_is_set(gr->adj[i], old_right))
+			/*
+				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) && !bitset_is_set(matched_left, i))
 					break;
 
 			/* If no such node can be found, exit. */
-			if(i >= gr->n_left)
+			if (i >= gr->n_left)
 				continue;
 
 			/* Else, we can improve this edge. */
@@ -103,10 +129,10 @@ static int apply_alternating_path(const bipartite_t *gr, int *matching,
 			assert(!bitset_is_set(matched_left, left));
 
 			bitset_andnot(tmp, matched_right);
-			if(bitset_popcnt(tmp) == 0)
+			if (bitset_is_empty(tmp))
 				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);
@@ -120,22 +146,31 @@ static int apply_alternating_path(const bipartite_t *gr, int *matching,
 
 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);
+	while (apply_alternating_path(gr, matching, matched_left, 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) {
+	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);
+	}
+}