include: sys: util_macro: add IS_BIT_MASK()/IS_SHIFTED_BIT_MASK() (8eff4b60) · Commits · Wenxi XU / zephyr

Add IS_BIT_MASK() macro for determining whether a value is set bits continuously from the LSB. This macro is not dependent on bit-width and works in contrast to BIT_MASK() and BIT64_MASK(). IS_SHIFTED_BIT_MASK() is a version of IS_BIT_MASK() that allows setting the start bit of continuous bits. Signed-off-by:

TOKITA Hiroshi <tokita.hiroshi@fujitsu.com>

include/zephyr/sys/util_macro.h

+17 −0

Original line number	Diff line number	Diff line
		@@ -73,6 +73,23 @@ extern "C" {
		*/
		#define BIT64_MASK(n) (BIT64(n) - 1ULL)

		/**
		* @brief Check if bits are set continuously from the specified bit
		*
		* The macro is not dependent on the bit-width.
		*
		* @param m Check whether the bits are set continuously or not.
		* @param s Specify the lowest bit for that is continuously set bits.
		*/
		#define IS_SHIFTED_BIT_MASK(m, s) (!(((m) >> (s)) & (((m) >> (s)) + 1U)))

		/**
		* @brief Check if bits are set continuously from the LSB.
		*
		* @param m Check whether the bits are set continuously from LSB.
		*/
		#define IS_BIT_MASK(m) IS_SHIFTED_BIT_MASK(m, 0)

		/**
		* @brief Check for macro definition in compiler-visible expressions
		*

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