sys: util: add a sign_extend and sign_extend_64 functions (5bb9b129) · Commits · Wenxi XU / zephyr

include/zephyr/sys/util.h

+31 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,7 @@

		#ifndef _ASMLANGUAGE

		#include <zephyr/sys/__assert.h>
		#include <zephyr/types.h>
		#include <stddef.h>
		#include <stdint.h>
		@@ -567,6 +568,36 @@ static inline uint8_t bin2bcd(uint8_t bin)
		*/
		uint8_t u8_to_dec(char *buf, uint8_t buflen, uint8_t value);

		/**
		* @brief Sign extend an 8, 16 or 32 bit value using the index bit as sign bit.
		*
		* @param value The value to sign expand.
		* @param index 0 based bit index to sign bit (0 to 31)
		*/
		static inline int32_t sign_extend(uint32_t value, uint8_t index)
		{
		__ASSERT_NO_MSG(index <= 31);

		uint8_t shift = 31 - index;

		return (int32_t)(value << shift) >> shift;
		}

		/**
		* @brief Sign extend a 64 bit value using the index bit as sign bit.
		*
		* @param value The value to sign expand.
		* @param index 0 based bit index to sign bit (0 to 63)
		*/
		static inline int64_t sign_extend_64(uint64_t value, uint8_t index)
		{
		__ASSERT_NO_MSG(index <= 63);

		uint8_t shift = 63 - index;

		return (int64_t)(value << shift) >> shift;
		}

		/**
		* @brief Properly truncate a NULL-terminated UTF-8 string
		*