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+ if (Py_SIZE(left) != 0) {
+ if (Py_SIZE(right) != 0) {
+
+#ifdef HAVE_LONG_LONG
+ mul = PyLong_FromLongLong(
+ (long long)SINGLE_DIGIT_LONG_AS_LONG(left) *
+ SINGLE_DIGIT_LONG_AS_LONG(right));
+#else
+ mul = PyNumber_Multiply(left, right);
+#endif
Why don't you use the same code than long_mul() (you need #include "longintrepr.h")?
----------------
 stwodigits v = (stwodigits)(MEDIUM_VALUE(a)) * MEDIUM_VALUE(b);
#ifdef HAVE_LONG_LONG
 return PyLong_FromLongLong((PY_LONG_LONG)v);
#else
 /* if we don't have long long then we're almost certainly
 using 15-bit digits, so v will fit in a long. In the
 unlikely event that we're using 30-bit digits on a platform
 without long long, a large v will just cause us to fall
 through to the general multiplication code below. */
 if (v >= LONG_MIN && v <= LONG_MAX)
 return PyLong_FromLong((long)v);
#endif
----------------
I guess that long_mul() was always well optimized, no need to experiment something new.