The AND and OR operators are evaluated from left to right. All the ANDs are done before all the OR's. So your expression would be executed in the following order:
b1 & b2
b2 & b3
(b1 & b2) | (b2 & b3)
(b1 & b2) | (b2 & b3) | b2
If you are combining bitwise and logical operators, all the bitwise are evaluated first.
Sun has a
chart on this and all the other operators.