What is faster (x < 0) or (x == -1)?

Question

Variable x is int with possible values: -1, 0, 1, 2, 3. Which expression will be faster (in CPU ticks):

1. (x < 0)
2. (x == -1)
         


        

Answer 1

Nikolay, you write:

It's actually bottleneck operator in the high-load program. Performance in this 1-2 strings is much more valuable than readability...

All bottlenecks are usually this small, even in perfect design with perfect algorithms (though there is no such). I do high-load DNA processing and know my field and my algorithms quite well

If so, why not to do next:

1. get timer, set it to 0;
2. compile your high-load program with (x < 0);
3. start your program and timer;
4. on program end look at the timer and remember result1.
5. same as 1;
6. compile your high-load program with (x == -1);
7. same as 3;
8. on program end look at the timer and remember result2.
9. compare result1 and result2.

You'll get the Answer.