Wow, thanks! That explains it.

The problem is rather that the way the perfs are measured is biased ("like usual"...?)

Considering the inputs used, the VERY GREAT MAJORITY of the outputs are -1. That means that what is measured is actually:

• v1:
  • call + arithmetic
  • compare
  • return
• v2:
  • call
  • store
  • load + arithmetic
  • compare
  • return

So, yeah, v2 is ofc a tiny bit slower.

Now, if you try with a perfect square as input for each call, the result will be the opposite:

1st variant: 2.9085514545440674
2nd variant: 2.345383644104004

I know that this is old, but why is it slower? Does the assignment really add more time than recalculating the sqrt?

This calulates sqrt(sq) twice. Is it more efficient to let s = sqrt(sq) and then use s?