> So, how again can something written in C perform faster than...something written in C?
Easy. JVM has runtime information it can use that C compiler simply doesn't have. There are some synthetic benchmarks that show how "java is faster than C".
Easy. JVM has runtime information it can use that C compiler simply doesn't have. There are some synthetic benchmarks that show how "java is faster than C".
Even that assumes that your program does not significantly shift its behavior mid-execution--in fact, you're optimizing for the average, not the current case.
One of the coolest JIT things is ability to inline virtual calls. Think about that, I could have my code calling a 3rd party library calling another 3rd party library thru 10 levels of stack and if all that call ever returns is "false", then JIT will optimize right through all that.
I don't believe PGO does virtual call inlining. That's a C++ nonstarter. In C, the equivalent would be inlining for function pointer calls.