"Even though it may seem that C compilers produce comparable
code, the opposite is true. A switch() statement is transformed to
a jump table by GCC and TurboC. XL C produces something that is
comparable to a long "if..elif..elif..endif" construction. In order
to accommodate XL C, the most often used tokens are in the
beginning of the switch() statement. That's what makes performance
such a difficult issue. What works for one compiler doesn't work
for another. That's why more and more products – like the
Linux kernel itself – are bound to one particular compiler or
even one particular version of a compiler."
