The version 16 of Maple does not know the function "pow", it is replaced by "power". Nevertheless, the codegen[optimize] procedure still generates it! Moreower, it's not optimal even to write poser(..., 1/2) as, most probably, the function sqrt must run faster.
Here's an example: (the function being optimized just contains some nested square roots)
> iang10 := [codegen[optimize](Re(int11), tryhard)];
[ 2 t17