small changes to make unionfind a tiny bit more efficient and easier to use

[libfirm] / include / libfirm / adt / unionfind.h

diff --git a/include/libfirm/adt/unionfind.h b/include/libfirm/adt/unionfind.h
index 5e1cb47..f2ee4cd 100644 (file)
--- a/include/libfirm/adt/unionfind.h
+++ b/include/libfirm/adt/unionfind.h
@@ -37,13 +37,13 @@
  * Call this to initialize an array of @p count elements to be used by the
  * union find functions.
  *
- * @param data The array (you have to allocate it yourself)
- * @param from The first element that should be initialized
- * @param to   the index of the first element which is not initialized anymore
+ * @param data    The array (you have to allocate it yourself)
+ * @param n_elems number of elements handled by the datastructure
  */
-static inline void uf_init(int* data, int from, int to) {
-       int i;
-       for(i = from; i < to; ++i) {
+static inline void uf_init(int* data, size_t n_elems)
+{
+       size_t i;
+       for(i = 0; i < n_elems; ++i) {
                data[i] = -1;
        }
 }
@@ -58,15 +58,18 @@ static inline void uf_init(int* data, int from, int to) {
  * @return             0 if the new union set is represented by set1, 1 if it is
  *              represented by set2
  */
-static inline int uf_union(int* data, int set1, int set2) {
-       int d1 = data[set1];
-       int d2 = data[set2];
+static inline int uf_union(int* data, int set1, int set2)
+{
+       int d1;
+       int d2;
        int newcount;
 
        if(set1 == set2)
                return 0;
 
        /* need 2 set representatives */
+       d1 = data[set1];
+       d2 = data[set2];
        assert(d1 < 0 && d2 < 0);
 
        newcount = d1 + d2;
@@ -91,7 +94,8 @@ static inline int uf_union(int* data, int set1, int set2) {
  * @param e            The element
  * @return             The representative of the set that contains @p e
  */
-static inline int uf_find(int* data, int e) {
+static inline int uf_find(int* data, int e)
+{
        /* go through list to find representative */
        int repr = e;
        while(data[repr] >= 0) {
@@ -108,4 +112,4 @@ static inline int uf_find(int* data, int e) {
        return repr;
 }
 
-#endif /* FIRM_ADT_UNIONFIND_H */
+#endif