Question

Is the code

 while(currentLine <= endLine)  
  {
     // more code
     currentLine++;  
  }

equivalent to

 while(currentLine < endLine || currentLine == endLine)
  {
     // more code
     currentLine++;   
  }

in terms of performance?

Answer 1

The <= operation typically compiles down into a single bytecode instruction if_icmple or ifle. How the JVM interprets that is typically machine-dependent, but most hardware has support to evaluate < and <= as a single instruction. Consequently, you should probably expect the performance for <= to be the same as <.

The Java compiler can potentially rewrite the second code as the first, meaning that there will be no performance penalty. However, this is an implementation detail.

Generally speaking, don’t worry about these sorts of microoptimizations unless you are sure that they’re the reason for a performance bottleneck. It’s extremely rare that decisions like this will have a profound effect on program runtime.

Hope this helps!