May 26, 2018
Turn off Math::Symbolic simplification
This module offers facilities to turn off the builtin MathSymbolic simplification routines and replace them with routines that just clone the objects. You may want to do this in cases where the simplification routines fail to simplify the MathSymbolic trees and waste a lot of CPU time. For example, calculating the first order Taylor polynomial of a moderately complex test function was sped up by 100 on my machine.
A word of caution, however If you turn off the simplification routines, some procedures may produce very, very large trees. One such procedure would be the consecutive application of many derivatives to a product without intermediate simplification. This would yield exponential growth of nodes. And may, in fact, still do if you keep the simplification heuristics turned on because most expressions cannot be simplified significantly.