sys: util: Add gcd and lcm utilities

Add helpers to compute Greates Common Divisor (GCD) and Least Common
Multiple (LCM).

Signed-off-by: Phi Bang Nguyen <[email protected]>
Signed-off-by: Trung Hieu Le <[email protected]>

Author: ngphibang

include/zephyr/sys/util.h

@@ -1038,6 +1038,61 @@ static inline size_t sys_count_bits(const void *value, size_t len)
  */
 #define SIGN(x) ((x > 0) - (x < 0))
 
+/**
+ * @brief Compute the Greatest Common Divisor (GCD) of two integers
+ * using the Euclidean algorithm.
+ *
+ * @param a First integer
+ * @param b Second integer
+ *
+ * @return The greatest common divisor of a and b, always returns a positive value.
+ *         If one of the parameters is 0, returns the absolute value of the other parameter.
+ */
+static inline int gcd(int a, int b)
+{
+	int abs_a = (a < 0) ? -a : a;
+	int abs_b = (b < 0) ? -b : b;
+
+	if (abs_a == 0) {
+		return abs_b;
+	}
+	if (abs_b == 0) {
+		return abs_a;
+	}
+
+	int c = abs_a % abs_b;
+
+	while (c != 0) {
+		abs_a = abs_b;
+		abs_b = c;
+		c = abs_a % abs_b;
+	}
+
+	return abs_b;
+}
+
+/**
+ * @brief Compute the Least Common Multiple (LCM) of two integers.
+ *
+ * @param a First integer
+ * @param b Second integer
+ *
+ * @retval The least common multiple of a and b.
+ * @retval 0 if either input is 0.
+ */
+static inline int lcm(int a, int b)
+{
+	if (a == 0 || b == 0) {
+		return 0;
+	}
+
+	int abs_a = (a < 0) ? -a : a;
+	int abs_b = (b < 0) ? -b : b;
+	int gcd_result = gcd(a, b);
+
+	return (abs_a / gcd_result) * abs_b;
+}
+
 #ifdef __cplusplus
 }
 #endif