3 ms·

Whoops, I guess I asked the wrong question. Are small integers in Python as fast as integers in C?

• lmm 11y ago
  Theoretically they're supposed to be (in practice it's hard to tell given how slow the rest of the language is and so I wouldn't be surprised if there were undiscovered implementation issues, but they should be). The case where you do trap an overflow and redo the calculation with bignums is of course a bit slower than doing it with bignums in the first place so it's not a completely free lunch (though AIUI the bignum calculation takes substantially longer than the trapped attempt at doing it with fixnums so it doesn't really matter).
  • shultays 11y ago
    How so? Does not python add some checks to see if an operation will overflow or not? Or something like that?
    • lmm 11y ago
      AIUI trapping on overflow is usually supported at the hardware level, so it's no overhead unless an overflow actually happens. (This is outside my area of expertise though - it's possible I'm wrong and they have to explicitly check the carry flag or some such, at least on some platforms)
  • cousin_it 11y ago
    I thought Python integers were PyObject's? That should slow things down a lot.