- kill keep-alive edges to dead blocks before doing apply_result(),

[libfirm] / ir / adt / bipartite.c

diff --git a/ir/adt/bipartite.c b/ir/adt/bipartite.c
index 493f72f..2acb390 100644 (file)
--- 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
+ * @cvs-id $Id$
+ */
+#include "config.h"
 
 #include <stdio.h>
 #include <assert.h>
@@ -8,18 +34,16 @@
 
 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)
                gr->adj[i] = bitset_malloc(n_right);
@@ -58,7 +82,7 @@ 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];
@@ -79,10 +103,12 @@ 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. */
@@ -106,7 +132,7 @@ 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);
@@ -115,29 +141,34 @@ 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);
+       }
+}