... > I had another look at why the cast is even needed for atomic_cmpxchg(), > and as Matt describes the problem here is that atomic_t contains a > signed 'int', but cmpxchg() takes an 'unsigned long' argument, and > converting between the two leads to a 64-bit sign-extension of > negative 32-bit atomics. How about: signed_var + 0u + 0ull; Converts 32bit signed to 64bit unsigned without sign extension. Compiler will throw it all away if not needed. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
