Index: uspace/lib/libc/include/adt/gcdlcm.h
===================================================================
--- uspace/lib/libc/include/adt/gcdlcm.h	(revision d68e4d573ccb8f5b2c980725f2f3c84831e0c8b5)
+++ uspace/lib/libc/include/adt/gcdlcm.h	(revision d68e4d573ccb8f5b2c980725f2f3c84831e0c8b5)
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2009 Martin Decky
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libc
+ * @{
+ */
+/** @file
+ */
+
+#ifndef LIBC_GCDLCM_H_
+#define LIBC_GCDLCM_H_
+
+#include <sys/types.h>
+
+#define DECLARE_GCD(type, name) \
+	static inline type name(type a, type b) \
+	{ \
+		if (a == 0) \
+			return b; \
+		 \
+		while (b != 0) { \
+			if (a > b) \
+				a -= b; \
+			else \
+				b -= a; \
+		} \
+		 \
+		return a; \
+	}
+
+#define DECLARE_LCM(type, name, gcd) \
+	static inline type name(type a, type b) \
+	{ \
+		return (a * b) / gcd(a, b); \
+	}
+
+DECLARE_GCD(uint32_t, gcd32);
+DECLARE_GCD(uint64_t, gcd64);
+DECLARE_GCD(size_t, gcd);
+
+DECLARE_LCM(uint32_t, lcm32, gcd32);
+DECLARE_LCM(uint64_t, lcm64, gcd64);
+DECLARE_LCM(size_t, lcm, gcd);
+
+#endif
+
+/** @}
+ */