Execution Speed in 2015a vs. 2014b

I'm relatively new to MatLab, and started out with 2014b, where I wrote a finite difference code that calls a small function to calculate a temperature-dependent property. Here is the small function:

   function [cp] = heat_capacity_exp(T)
   Tmin = 325; %Boundary between low temp cubic and mid temp quartic
   Tmax = 350; %Boundary between high temp cubic and mid temp quartic

   if(T <= Tmax)
  if(T >= Tmin)
    cp = 10^7*(-55805.67146 + 661.53705*T - 2.93933*T^2 + 0.0058*T^3 - 4.2937e-6*T^4); %ergs/g-C
  else 
    cp = 10^7*(4.14032 + 0.00715*T - 1.28539e-5*T^2 + 2.1596e-8*T^3); %ergs/g-C
  end
   else
  cp = 10^7*(5.87441 + 0.0193*T - 9.82429e-5*T^2 + 1.20361e-7*T^3); %ergs/g-C
   end
   return

I used the "Run and Time" process on my entire code and tracked the slowdown to the above function. On 2014b executing this function (my test run called it 11340000 times) took 26.416 sec, but on 2015a it takes 38.346 sec. I'm not sure if the handling of polynomials has changed from 2014b to 2015a, but a 45% increase in execution time seems pretty bad.

Has polynomial handling been changed between 2014b and 2015a? Is there any reason why the code is running so much slower? Thanks!

UPDATE: Profiler indicates that significant time is spent on the "return" and "end" function, not sure why.

UPDATE 2: In further tests, the profiler tells me that the lines that execute (all the ones shown) take up 38% of the time, and that the remaining 62% of the time is taken up by "All other lines"... however, there are no other lines in the code. Why is nearly 2/3 of the time taken up by lines that don't exist?