Bukkit/CraftBukkit — comment on commit 6d198be88856379f14f70b8e2d1ace66bd6f1ab7
File: src/main/java/org/bukkit/craftbukkit/CraftChunk.java line 256
By HenryLoenwind:

Sry, I should have explained what I meant. "world.getHandle()", "(x << 4)" and "(z << 4)" will be re-executed 256 times. The first one cannot be optimized away by the compiler (because the runtime world object's method might have side effects), and for the other two, I expect the Java compiler to be not good enough to optimize them out of the loop. The shifts might get eaten by modern CPU's pipeline, but the method call is heavy.