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.

1 files changed, 9 insertions, 0 deletions

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_FromUnsignedLong(unsigned long);
 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 *);