1 files changed, 30 insertions, 0 deletions
diff --git a/mdk-stage1/dietlibc/lib/rand_r.c b/mdk-stage1/dietlibc/lib/rand_r.c
new file mode 100644
index 000000000..55f8303bc
--- /dev/null
+++ b/mdk-stage1/dietlibc/lib/rand_r.c
@@ -0,0 +1,30 @@
+/*
+   Copyright (C) 2002 Luc Van Oostenryck
+
+   This is free software. You can redistribute and
+   modify it under the terms of the GNU General Public
+   Public License.
+*/
+
+#include <stdlib.h>
+#include <stdint.h>
+
+/* Knuth's TAOCP section 3.6 */
+#define	M	((1U<<31) -1)
+#define	A	48271
+#define	Q	44488		// M/A
+#define	R	3399		// M%A; R < Q !!!
+
+// FIXME: ISO C/SuS want a longer period
+
+int rand_r(unsigned int* seed)
+{   int32_t X;
+
+    X = *seed;
+    X = A*(X%Q) - R * (int32_t) (X/Q);
+    if (X < 0)
+	X += M;
+
+    *seed = X;
+    return X;
+}