Introduce new private API function _PyLong_AsScaledDouble. Not used yet,
but will be the foundation for Good Things:
+ Speed PyLong_AsDouble.
+ Give PyLong_AsDouble the ability to detect overflow.
+ Make true division of long/long nearly as accurate as possible (no
spurious infinities or NaNs).
+ Return non-insane results from math.log and math.log10 when passing a
long that can't be approximated by a double better than HUGE_VAL.
diff --git a/Include/longobject.h b/Include/longobject.h
index 5d1ea0a..e592891 100644
--- a/Include/longobject.h
+++ b/Include/longobject.h
@@ -18,6 +18,15 @@
extern DL_IMPORT(PyObject *) PyLong_FromDouble(double);
extern DL_IMPORT(long) PyLong_AsLong(PyObject *);
extern DL_IMPORT(unsigned long) PyLong_AsUnsignedLong(PyObject *);
+
+/* _PyLong_AsScaledDouble returns a double x and an exponent e such that
+ the true value is approximately equal to x * 2**(SHIFT*e). e is >= 0.
+ x is 0.0 if and only if the input is 0 (in which case, e and x are both
+ zeroes). Overflow is impossible. Note that the exponent returned must
+ be multiplied by SHIFT! There may not be enough room in an int to store
+ e*SHIFT directly. */
+extern DL_IMPORT(double) _PyLong_AsScaledDouble(PyObject *vv, int *e);
+
extern DL_IMPORT(double) PyLong_AsDouble(PyObject *);
extern DL_IMPORT(PyObject *) PyLong_FromVoidPtr(void *);
extern DL_IMPORT(void *) PyLong_AsVoidPtr(PyObject *);