That's why I would like the simple
if (v == w) return 0;
integrated into the ceval loop right along the INT-compare optimization.
Maybe this could be done as follows:
if (v == w && PyString_CheckExact(v)) return 0;
Maybe I'm missing some context here: where is this fragment supposed to go to? into ceval.c:COMPARE_OP? What is the "return 0;" doing then? In any case, I think measurements should show how much speed improvement is gained by taking this short-cut. It sounds nice in theory, but ... I just added the block else if ((v == w) && (oparg == EQ) && PyString_CheckExact(v)) { x = Py_True; Py_INCREF(x); } into the code. In an application that almost exclusively does COMPARE_OPs on identical strings, I got a 30% speed-up. OTOH, this same code caused a 10% slowdown if I converted the "==" into "<>". In a real application, total speed-up will depend on two things: - how many COMPARE_OPs are done in the code? - how many of those compare identical strings for equality? Running the PyXML test suite, I counted 120000 cases where slow_compare was done, and only 700 cases identical strings were compared for equality. Regards, Martin