I have used switch statements and arrays of function pointers in the past to achieve a little speed boost in situations where there were potentially many unpredictable branches, replacing those many unpredictable branches with one unpredictable branch (the jump table). I was wondering if there are limits to this approach. For instance, is there a point at which adding more elements to the jump table would begin causing a slow down? Even if it is a large, seemingly ridiculous limit, I''m still interested in knowing what it is. The only thing I can think of is that if the jump table gets so large that the table can no longer fit in the cpu cache, then a slowdown could occur.

nope.

The upper limit is somewhere around not being able to fit the table into memory.