mod8()

LIB8STATIC_ALWAYS_INLINE uint8_t mod8	(	uint8_t	a,
		uint8_t	m )

Calculate the remainder of one unsigned 8-bit value divided by anoter, aka A % M.

Implemented by repeated subtraction, which is very compact, and very fast if A is "probably" less than M. If A is a large multiple of M, the loop has to execute multiple times. However, even in that case, the loop is only two instructions long on AVR, i.e., quick.

Parameters

a	dividend byte
m	divisor byte

Returns

remainder of a / m (i.e. a % m)

Definition at line 361 of file math8.h.

                                                            {
#if defined(__AVR__)
    asm volatile("L_%=:  sub %[a],%[m]    \n\t"
                 "       brcc L_%=        \n\t"
                 "       add %[a],%[m]    \n\t"
                 : [a] "+r"(a)
                 : [m] "r"(m));
#else
    while (a >= m)
        a -= m;
#endif
    return a;
}

References LIB8STATIC_ALWAYS_INLINE.