I like the extra parens in the if condition. It's genius. On the face of it, it appears that the parens are to ensure correct operator precedence because a bit

I like the extra parens in the if condition. It's genius. On the face of it, it appears that the parens are to ensure correct operator precedence because a bitwise OR is used (a common idiom because bitwise operators have the wrong precedence versus comparison in C). But that's not what the parens are really for! They are there because gcc complains about assignments inside of conditionals unless you put parens around it.