2 ^ 32, 1 << 32, 2 << 31

@time 1 << 31
@time 2 ^ 31

function roll(x, n)
    return (x << n) % (1 << 32) + (x >> (32 - n))
end

a = 0x11111111
b = 0x01020304
c = 0x77777777
d = 0x01234567
println(c + d)
println(0x789abcde)
c = c + d
println(xor(b, c))
println(0x7998bfda)
b = xor(b, c)
println(roll(b, 7))
println(0xcc5fed3c)

function quarter_round(a, b, c, d)
    a = (a + b) % (1 << 32)
    d = roll(xor(d, a), 16)
    c = (c + d) % (1 << 32)
    b = roll(xor(b, c), 12)
    a = (a + b) % (1 << 32)
    d = roll(xor(d, a),  8)
    c = (c + d) % (1 << 32)
    b = roll(xor(b, c),  7)
    return a, b, c, d
end

a = 0x11111111
b = 0x01020304
c = 0x9b8d6f43
d = 0x01234567

quarter_round(a, b, c, d)

typeof(a)

0xea2a92f4, 0xcb1cf8ce, 0x4581472e, 0x5881c4bb