156 // Fetch count bits starting at bit start from value

   156 /// Fetch n bits starting at bit s from x

   157 #define GB(value, start, count) (((value) >> (start)) & ((1 << (count)) - 1))

   157 #define GB(x, s, n) (((x) >> (s)) & ((1 << (n)) - 1))

   158 // Set count bits in value starting at bit start to data

   158 /// Set n bits in x starting at bit s to d

   159 #define SB(value, start, count, data) ((value) = ((value) & ~(((1 << (count)) - 1) << (start))) | ((data) << (start)))

   159 #define SB(x, s, n, d) ((x) = ((x) & ~(((1 << (n)) - 1) << (s))) | ((d) << (s)))

   160 

   161 /**

   162  * ROtate x Left/Right by n (must be >= 0)

   163  * @note Assumes a byte has 8 bits

   164  */

   165 #define ROL(x, n) ((x) << (n) | (x) >> (sizeof(x) * 8 - (n)))

   166 #define ROR(x, n) ((x) >> (n) | (x) << (sizeof(x) * 8 - (n)))