1 files changed, 71 insertions, 0 deletions
diff --git a/intern/opennl/superlu/relax_snode.c b/intern/opennl/superlu/relax_snode.c
new file mode 100644
index 00000000000..549f3fcf873
--- /dev/null
+++ b/intern/opennl/superlu/relax_snode.c
@@ -0,0 +1,71 @@
+/*
+ * -- SuperLU routine (version 2.0) --
+ * Univ. of California Berkeley, Xerox Palo Alto Research Center,
+ * and Lawrence Berkeley National Lab.
+ * November 15, 1997
+ *
+ */
+/*
+  Copyright (c) 1994 by Xerox Corporation.  All rights reserved.
+ 
+  THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY
+  EXPRESSED OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
+ 
+  Permission is hereby granted to use or copy this program for any
+  purpose, provided the above notices are retained on all copies.
+  Permission to modify the code and to distribute modified code is
+  granted, provided the above notices are retained, and a notice that
+  the code was modified is included with the above copyright notice.
+*/
+
+#include "ssp_defs.h"
+
+void
+relax_snode (
+	     const     int n,
+	     int       *et,           /* column elimination tree */
+	     const int relax_columns, /* max no of columns allowed in a
+					 relaxed snode */
+	     int       *descendants,  /* no of descendants of each node
+					 in the etree */
+	     int       *relax_end     /* last column in a supernode */
+	     )
+{
+/*
+ * Purpose
+ * =======
+ *    relax_snode() - Identify the initial relaxed supernodes, assuming that 
+ *    the matrix has been reordered according to the postorder of the etree.
+ *
+ */ 
+    register int j, parent;
+    register int snode_start;	/* beginning of a snode */
+    
+    ifill (relax_end, n, EMPTY);
+    for (j = 0; j < n; j++) descendants[j] = 0;
+
+    /* Compute the number of descendants of each node in the etree */
+    for (j = 0; j < n; j++) {
+	parent = et[j];
+	if ( parent != n )  /* not the dummy root */
+	    descendants[parent] += descendants[j] + 1;
+    }
+
+    /* Identify the relaxed supernodes by postorder traversal of the etree. */
+    for (j = 0; j < n; ) { 
+     	parent = et[j];
+        snode_start = j;
+ 	while ( parent != n && descendants[parent] < relax_columns ) {
+	    j = parent;
+	    parent = et[j];
+	}
+	/* Found a supernode with j being the last column. */
+	relax_end[snode_start] = j;		/* Last column is recorded */
+	j++;
+	/* Search for a new leaf */
+	while ( descendants[j] != 0 && j < n ) j++;
+    }
+
+    /*printf("No of relaxed snodes: %d; relaxed columns: %d\n", 
+		nsuper, no_relaxed_col); */
+}