I saw this change to speedup the mapgen: https://github.com/celeron55/minetest/commit/b701f8a878b7c76a33d7c3540a4b5e9c6e6b31ac
It replaced the slow pow function.
Then I stumpled upon this:
https://github.com/jordan4ibanez/minetest/commit/37d6c3a2f19854caf6dfeb352cb9f6c50bb52757
Ok, it's jordan4ibanez's fork, but it's the same in celeron55's in camera.cpp:
There is usage of slow sin- and pow-function in the digging and bobbing animation. There are faster ways for the sin-function: lookup-tables, approximations, interpolations... http://stackoverflow.com/questions/6091837/sin-and-cos-are-slow-is-there-an-alternatve
Is this worth to be optimized or is it fast enough because it's called only sporadically?