python · gnprice · Aug 1, 2019 · Aug 11, 2019
diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-08-10-14-15-48.bpo-37812.jkh0Wp.rst b/Misc/NEWS.d/next/Core and Builtins/2019-08-10-14-15-48.bpo-37812.jkh0Wp.rst
@@ -0,0 +1,6 @@
+The "small int" optimization is now unconditionally enabled.  This
+optimization was introduced in Python 1.0.1, and means that :class:`int`
+values from -5 through 256 are pre-initialized rather than constructed on
+demand.  The option was always enabled unless certain never-documented
+preprocessor macros were defined to 0 at build time; now it is always
+enabled, simplifying the logic.  Patch by Greg Price.
diff --git a/Objects/longobject.c b/Objects/longobject.c
@@ -34,7 +34,6 @@ _Py_IDENTIFIER(big);
 PyObject *_PyLong_Zero = NULL;
 PyObject *_PyLong_One = NULL;

-#if NSMALLNEGINTS + NSMALLPOSINTS > 0
 /* Small integers are preallocated in this array so that they
   can be shared.
   The integers that are preallocated are those in the range
@@ -77,10 +76,6 @@ maybe_small_long(PyLongObject *v)
    }
    return v;
 }
-#else
-#define CHECK_SMALL_INT(ival)
-#define maybe_small_long(val) (val)
-#endif

 /* If a freshly-allocated int is already shared, it must
   be a small integer, so negating it must go to PyLong_FromLong */
@@ -5808,7 +5803,6 @@ PyLong_GetInfo(void)
 int
 _PyLong_Init(void)
 {
-#if NSMALLNEGINTS + NSMALLPOSINTS > 0
    int ival, size;
    PyLongObject *v = small_ints;

@@ -5836,7 +5830,7 @@ _PyLong_Init(void)
        Py_SIZE(v) = size;
        v->ob_digit[0] = (digit)abs(ival);
    }
-#endif
+
    _PyLong_Zero = PyLong_FromLong(0);
    if (_PyLong_Zero == NULL)
        return 0;
@@ -5862,12 +5856,11 @@ PyLong_Fini(void)
       reinitializations will fail. */
    Py_CLEAR(_PyLong_One);
    Py_CLEAR(_PyLong_Zero);
-#if NSMALLNEGINTS + NSMALLPOSINTS > 0
+
    int i;
    PyLongObject *v = small_ints;
    for (i = 0; i < NSMALLNEGINTS + NSMALLPOSINTS; i++, v++) {
        _Py_DEC_REFTOTAL;
        _Py_ForgetReference((PyObject*)v);
    }
-#endif
 }