This particular loop goes through millions of iterations. Now the difference in run times between using a sub versus copying and pasting the code was under 1 minute,

That doesn't really paint a picture.
How long does a normal run take? 10 minutes? 2 minutes? 10 Hours?
How long does the other one take? 9 minutes? 1 minute? 9 hours and 59 minutes?
What's the percent difference? (       %10?       %50?       %0.16?)

If the increase is %50, i'd say go for it (what broquaint showed).
If it's %10 percent, maybe, but if it's 0.16? Forget it.

MJD says you can't just make shit up and expect the computer to know what you mean, retardo! I run a Win32 PPM repository for perl 5.6x+5.8x. I take requests. ** The Third rule of perl club is a statement of fact: pod is sexy.