4 ms·

In cases where performance actually matters, just avoid bit-twiddle in high-level languages. It sucks too much. You'll probably waste less time on optimizations

• mbell 15y ago
  >You'll probably waste less time on optimizations by offloading the biggest bottlenecks to C/C++ with the native/extension interfaces in your high-level language of choice. In reality this often requires a heavy refactor to actually work. In Java with JNI for instance the overhead of calling native methods is actually rather high, over 200 cpu cycles in many cases. The stack often has to be re-arranged, a CPU stall is usually caused and in the case of most data types passed to the native function, they have to be copied (last i knew java.nio buffers were the only types that weren't copied). Point is, just moving your "hot function" to C / C++ and calling with JNI doesn't work unless that function is rarely called and does a lot of work internally. More often the "hot function" is something that is called thousands of times and moving something like that to JNI is just as likely to kill performance as help it. You'd have to abstract away an entire module of work and minimize its call surface to JNI to achieve your goal.