BUG in dec2hex

[Stephen23]

You do not explain what the problem is.

Note that your last example uses DOUBLE class and not UINT64, which clearly has a different bit pattern:

u = bitxor(uint64(0xFF000000),0xFFFFFFFFFFFFFFFF)

u = uint64 18446744069431361535

dec2hex(u)

ans = 'FFFFFFFF00FFFFFF'

d = double(u) % The same value you entered by hand

d = 1.8447e+19

dec2hex(d)

ans = 'FFFFFFFF01000000'