*
* -->
*
+ * \defgroup macros General purpose macros
+ * \ingroup core
+ * \{
+ *
* \brief Common and handy function macros
*
* \author Bernie Innocenti <bernie@codewiz.org>
/**
* Perform an integer division rounding the result to the upper int value.
- * \note \a divisor should preferibly be a costant, otherwise this macro generates
- * 2 division. Also divisor is evaluated twice.
+ * \note \a divisor is evaluated twice.
*/
#define DIV_ROUNDUP(dividend, divisor) (((dividend) + (divisor) - 1) / (divisor))
+
+/**
+ * Perform a multiply between the integer \a a and the float constant \a f.
+ *
+ * This macro can be used in order to avoid floating point arithmetics
+ * in expressions like this:
+ * \code
+ * int a, b;
+ * a = b * 0.5579652750;
+ * \endcode
+ *
+ * This macro rounds the floating point constant to a fraction,
+ * usign (2 ^ prec) as the denominator.
+ * For instance, with prec = 8, the constant 0.5579652750 will be rounded to:
+ * (143 / 256) = 0.55859375
+ * So, the former code will be transformed to:
+ * \code
+ * a = b * 143 / 256;
+ * \endcode
+ *
+ * Since the denominator is a power of 2, we rely on the compiler to optimize
+ * this to a right shift.
+ * So, when you have to multiply an integer by a float constant, this macro
+ * will not use the floating point arithmentics.
+ * The operation will be converted to a mul + shift, with a huge performance boost.
+ *
+ * \note \a f MUST be a constant in order gain performance benefits.
+ *
+ * \param a integer you want to multiply
+ * \param f floating point constant which you want to multply with \a a
+ * \param prec conversion precision, ranges from 1 to the number of bits in a long.
+ * The higher, the better the approximation of the float constant will be.
+ */
+#define INT_MULT(a, f, prec) (((a) * (long)((f) * (1 << (prec)) + 0.5)) >> (prec))
+
+
/** Round up \a x to an even multiple of the 2's power \a pad. */
#define ROUND_UP2(x, pad) (((x) + ((pad) - 1)) & ~((pad) - 1))
/** Check if \a x is an integer power of 2. */
#define IS_POW2(x) (!(bool)((x) & ((x)-1)))
+/** Check if \a x is aligned to \a byte_count bytes */
+#define IS_ALIGNED(x, byte_count) ((uintptr_t)(const void *)(x) % (byte_count) == 0)
+
/** Calculate a compile-time log2 for a uint8_t */
#define UINT8_LOG2(x) \
((x) < 2 ? 0 : \
*/
typedef uint32_t id_t;
+/**
+ * Check if a pointer is aligned to a certain power-of-2 size
+ */
+INLINE bool is_aligned(const void *addr, size_t size)
+{
+ return ((size_t)addr & (size - 1)) == 0;
+}
+
+/**
+ * Convert one 32bit bcd numbert to int.
+ */
+#define BCD_TO_INT_32BIT(bcd) \
+ ((uint32_t )((bcd) & 0xf) * 1 + \
+ (((bcd) >> 4) & 0xf) * 10 + \
+ (((bcd) >> 8) & 0xf) * 100 + \
+ (((bcd) >> 12) & 0xf) * 1000 + \
+ (((bcd) >> 16) & 0xf) * 10000 + \
+ (((bcd) >> 20) & 0xf) * 100000 + \
+ (((bcd) >> 24) & 0xf) * 1000000 + \
+ (((bcd) >> 28) & 0xf) * 10000000) \
+
+/**
+ * Extract chunk of bit from gived array (uint32_t type).
+ * \param resp array of bit 32bit aligned
+ * \param start bit position in array
+ * \param size of bit chuck from start
+ * \return uint32_t chunk value.
+ */
+#define UNSTUFF_BITS(resp, start, size) \
+ ({ \
+ const uint32_t __size = size; \
+ const uint32_t __mask = (__size < 32 ? 1 << __size : 0) - 1; \
+ const uint32_t __off = 3 - ((start) / 32); \
+ const uint32_t __shft = (start) & 31; \
+ uint32_t __res; \
+ \
+ __res = resp[__off] >> __shft; \
+ if (__size + __shft > 32) \
+ __res |= resp[__off-1] << ((32 - __shft) % 32); \
+ __res & __mask; \
+ })
+
+
+/** \} */ //defgroup macros
+
+
+/**
+ * Macro to unpack the ip addres from lwip format in 4 int
+ * \param addr is struct ip_addr ip_addr;
+ * \return for int variable separated from comma
+ *
+ * \code
+ * //Upack into 4 int the lwip ip address
+ * LOG_INFO("dhcp ok: ip = %d.%d.%d.%d\n", IP_ADDR_TO_INT_TUPLE(netif.ip_addr.addr));
+ * \endcode
+ */
+#define IP_ADDR_TO_INT_TUPLE(addr) \
+ (int)((addr) >> 0 & 0xff), \
+ (int)((addr) >> 8 & 0xff), \
+ (int)((addr) >> 16 & 0xff), \
+ (int)((addr) >> 24 & 0xff)
+
#endif /* MACROS_H */
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