Casio fx-991EX vs Hp 50g speed difference

[Albert Chan]

Thanks, Carsen for the test.

I think the transformed sine integral is faster because it converge slightly
faster, skipping 1 Simpson iteration (that is why the halved timing).

But, that is just lucky.

It could be the other way around, like the transformed exponential integral.
5X slow down possibly caused by 2 extra Simpson iteration for convergence.

Transformed integral is not really for performance, but to avoid false convergence.