lua 源代码中的 位操作源代码

#define resetbits(x,m)        ((x) &= cast(lu_byte, ~(m)))
#define setbits(x,m)        ((x) |= (m))
#define testbits(x,m)        ((x) & (m))
#define bitmask(b)        (1<<(b))
#define bit2mask(b1,b2)        (bitmask(b1) | bitmask(b2))
#define l_setbit(x,b)        setbits(x, bitmask(b))
#define resetbit(x,b)        resetbits(x, bitmask(b))
#define testbit(x,b)        testbits(x, bitmask(b))
#define set2bits(x,b1,b2)    setbits(x, (bit2mask(b1, b2)))
#define reset2bits(x,b1,b2)    resetbits(x, (bit2mask(b1, b2)))