A more interesting comparison would be the PyPy-generated native code for the expression versus the compiled code from Go. Comparing an interpreter with a compiler is generally uninteresting; the compiler almost always wins.
If you look at the code that comes out of various modern JITs you often will find really interesting differences in the native code they produce, even for simple constructs like arithmetic. Type checks, barriers, bailouts, etc - in addition to more mundane differences, like one using SSE to do floating point and the other using x87, and one JIT having a better register allocator.
If you look at the code that comes out of various modern JITs you often will find really interesting differences in the native code they produce, even for simple constructs like arithmetic. Type checks, barriers, bailouts, etc - in addition to more mundane differences, like one using SSE to do floating point and the other using x87, and one JIT having a better register allocator.