python · vstinner · Mar 31, 2026 · Mar 30, 2026
diff --git a/Include/internal/pycore_long.h b/Include/internal/pycore_long.h
@@ -64,7 +64,8 @@ PyAPI_FUNC(void) _PyLong_ExactDealloc(PyObject *self);
 #  error "_PY_NSMALLPOSINTS must be greater than or equal to 257"
 #endif

-#define _PY_IS_SMALL_INT(val) ((val) >= 0 && (val) < 256 && (val) < _PY_NSMALLPOSINTS)
+#define _PY_IS_SMALL_INT(val) \
+    (-_PY_NSMALLNEGINTS <= (val) && (val) < _PY_NSMALLPOSINTS)

 // Return a reference to the immortal zero singleton.
 // The function cannot return NULL.

diff --git a/Objects/longobject.c b/Objects/longobject.c
@@ -24,7 +24,7 @@ class int "PyObject *" "&PyLong_Type"

 #define medium_value(x) ((stwodigits)_PyLong_CompactValue(x))

-#define IS_SMALL_INT(ival) (-_PY_NSMALLNEGINTS <= (ival) && (ival) < _PY_NSMALLPOSINTS)
+#define IS_SMALL_INT(ival) _PY_IS_SMALL_INT(ival)
 #define IS_SMALL_UINT(ival) ((ival) < _PY_NSMALLPOSINTS)

 #define _MAX_STR_DIGITS_ERROR_FMT_TO_INT "Exceeds the limit (%d digits) for integer string conversion: value has %zd digits; use sys.set_int_max_str_digits() to increase the limit"

@@ -1397,7 +1397,7 @@ maybe_instr_make_load_smallint(cfg_instr *instr, PyObject *newconst,
        if (val == -1 && PyErr_Occurred()) {
            return -1;
        }
-        if (!overflow && _PY_IS_SMALL_INT(val)) {
+        if (!overflow && _PY_IS_SMALL_INT(val) && 0 <= val && val <= 255) {
            assert(_Py_IsImmortal(newconst));
            INSTR_SET_OP1(instr, LOAD_SMALL_INT, (int)val);
            return 1;