What? Arbitrary precision arithmetic implemented in a compiled language will be faster than the alternative. This is no great mystery. The same is true of essentially all low-level symbolic or numerical math algorithms. You need to get to a fairly high level before this stops being true.
You are missing the term "JIT", which would enable a host of runtime optimizations which include generating calls to some static piece of native code which performs addition.
Mathematica has symbolic and infinite-precision addition, so you can't automatically take advantage of obvious compiled code.
What? Arbitrary precision arithmetic implemented in a compiled language will be faster than the alternative. This is no great mystery. The same is true of essentially all low-level symbolic or numerical math algorithms. You need to get to a fairly high level before this stops being true.
You are missing the term "JIT", which would enable a host of runtime optimizations which include generating calls to some static piece of native code which performs addition.
But surely you can have a "fast path" that is implemented in the host language, right?