[math-fun] how long is long [was: reversing the order of bits in a word]

Speaking as someone who does this as his "day job", Joerg is right about longs, on 64 bit platforms, being 64 bits, except on Windows. The fairly standard compiler flag for this is "LP64", or some nearby variant (it's "_LP64" on gcc). LP64 is just shorthand for "longs and pointers are 64 bits". It also makes a good search string for more than you ever wanted to know on this subject. - John Aspinall