include: util: Add DIV_ROUND_CLOSEST helper (8fc91337) · Commits · Wenxi XU / zephyr

include/zephyr/sys/util.h

+19 −0

Original line number	Diff line number	Diff line
		@@ -259,6 +259,25 @@ extern "C" {
		*/
		#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))

		/**
		* @brief Divide and round to the nearest integer.
		*
		* Example:
		* @code{.c}
		* DIV_ROUND_CLOSEST(5, 2); // 3
		* DIV_ROUND_CLOSEST(5, -2); // -3
		* DIV_ROUND_CLOSEST(5, 3); // 2
		* @endcode
		*
		* @param n Numerator.
		* @param d Denominator.
		*
		* @return The result of @p n / @p d, rounded to the nearest integer.
		*/
		#define DIV_ROUND_CLOSEST(n, d) \
		((((n) < 0) ^ ((d) < 0)) ? ((n) - ((d) / 2)) / (d) : \
		((n) + ((d) / 2)) / (d))

		/**
		* @brief Ceiling function applied to @p numerator / @p divider as a fraction.
		* @deprecated Use DIV_ROUND_UP() instead.

+10 −0

Original line number	Diff line number	Diff line
		@@ -151,6 +151,11 @@ ZTEST(util_cxx, test_DIV_ROUND_UP)
		run_DIV_ROUND_UP();
		}

		ZTEST(util_cxx, test_DIV_ROUND_CLOSEST)
		{
		run_DIV_ROUND_CLOSEST();
		}

		ZTEST_SUITE(util_cxx, NULL, NULL, NULL, NULL, NULL);

		#if __cplusplus
		@@ -294,4 +299,9 @@ ZTEST(util_cc, test_DIV_ROUND_UP)
		run_DIV_ROUND_UP();
		}

		ZTEST(util_cc, test_DIV_ROUND_CLOSEST)
		{
		run_DIV_ROUND_CLOSEST();
		}

		ZTEST_SUITE(util_cc, NULL, NULL, NULL, NULL, NULL);

+13 −0

Original line number	Diff line number	Diff line
		@@ -615,3 +615,16 @@ void run_DIV_ROUND_UP(void)
		zassert_equal(DIV_ROUND_UP(1, 2), 1);
		zassert_equal(DIV_ROUND_UP(3, 2), 2);
		}

		void run_DIV_ROUND_CLOSEST(void)
		{
		zassert_equal(DIV_ROUND_CLOSEST(0, 1), 0);
		/* 5 / 2 = 2.5 -> 3 */
		zassert_equal(DIV_ROUND_CLOSEST(5, 2), 3);
		zassert_equal(DIV_ROUND_CLOSEST(5, -2), -3);
		zassert_equal(DIV_ROUND_CLOSEST(-5, 2), -3);
		zassert_equal(DIV_ROUND_CLOSEST(-5, -2), 3);
		/* 7 / 3 = 2.(3) -> 2 */
		zassert_equal(DIV_ROUND_CLOSEST(7, 3), 2);
		zassert_equal(DIV_ROUND_CLOSEST(-7, 3), -2);
		}