Add some guards and branch hints to the dict lookup optimisation code.

Cython/Compiler/Nodes.py

@@ -4354,7 +4354,7 @@ class OverrideCheckNode(StatNode):
                        " || (Py_TYPE(%s)->tp_flags & (Py_TPFLAGS_IS_ABSTRACT | Py_TPFLAGS_HEAPTYPE)))) {" % (
                 self_arg, self_arg))
 
-        code.putln("#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_PYTYPE_LOOKUP")
+        code.putln("#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_PYTYPE_LOOKUP && CYTHON_USE_TYPE_SLOTS")
         code.globalstate.use_utility_code(
             UtilityCode.load_cached("PyDictVersioning", "ObjectHandling.c"))
         # TODO: remove the object dict version check by 'inlining' the getattr implementation for methods.
@@ -4389,7 +4389,7 @@ class OverrideCheckNode(StatNode):
         # NOTE: it's not 100% sure that we catch the exact versions here that were used for the lookup,
         # but it is very unlikely that the versions change during lookup, and the type dict safe guard
         # should increase the chance of detecting such a case.
-        code.putln("#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_PYTYPE_LOOKUP")
+        code.putln("#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_PYTYPE_LOOKUP && CYTHON_USE_TYPE_SLOTS")
         code.putln("%s = __Pyx_get_tp_dict_version(%s);" % (
             Naming.tp_dict_version_temp, self_arg))
         code.putln("%s = __Pyx_get_object_dict_version(%s);" % (
@@ -4409,7 +4409,7 @@ class OverrideCheckNode(StatNode):
         code.put_decref_clear(func_node_temp, PyrexTypes.py_object_type)
         code.funcstate.release_temp(func_node_temp)
 
-        code.putln("#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_PYTYPE_LOOKUP")
+        code.putln("#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_PYTYPE_LOOKUP && CYTHON_USE_TYPE_SLOTS")
         code.putln("}")
         code.putln("#endif")
 

Cython/Utility/ObjectHandling.c

@@ -2402,7 +2402,7 @@ static PyObject* __Pyx_PyNumber_InPlaceMatrixMultiply(PyObject* x, PyObject* y)
 
 /////////////// PyDictVersioning.proto ///////////////
 
-#if CYTHON_USE_DICT_VERSIONS
+#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_TYPE_SLOTS
 #define __PYX_DICT_VERSION_INIT  ((PY_UINT64_T) -1)
 #define __PYX_GET_DICT_VERSION(dict)  (((PyDictObject*)(dict))->ma_version_tag)
 #define __PYX_UPDATE_DICT_CACHE(dict, value, cache_var, version_var) \
@@ -2432,24 +2432,28 @@ static CYTHON_INLINE int __Pyx_object_dict_version_matches(PyObject* obj, PY_UIN
 
 /////////////// PyDictVersioning ///////////////
 
-#if CYTHON_USE_DICT_VERSIONS
+#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_TYPE_SLOTS
 static CYTHON_INLINE PY_UINT64_T __Pyx_get_tp_dict_version(PyObject *obj) {
     PyObject *dict = Py_TYPE(obj)->tp_dict;
-    return dict ? __PYX_GET_DICT_VERSION(dict) : 0;
+    return likely(dict) ? __PYX_GET_DICT_VERSION(dict) : 0;
 }
 
 static CYTHON_INLINE PY_UINT64_T __Pyx_get_object_dict_version(PyObject *obj) {
     PyObject **dictptr = NULL;
     Py_ssize_t offset = Py_TYPE(obj)->tp_dictoffset;
     if (offset) {
-        dictptr = (offset > 0) ? (PyObject **) ((char *)obj + offset) : _PyObject_GetDictPtr(obj);
+#if CYTHON_COMPILING_IN_CPYTHON
+        dictptr = (likely(offset > 0)) ? (PyObject **) ((char *)obj + offset) : _PyObject_GetDictPtr(obj);
+#else
+        dictptr = _PyObject_GetDictPtr(obj);
+#endif
     }
     return (dictptr && *dictptr) ? __PYX_GET_DICT_VERSION(*dictptr) : 0;
 }
 
 static CYTHON_INLINE int __Pyx_object_dict_version_matches(PyObject* obj, PY_UINT64_T tp_dict_version, PY_UINT64_T obj_dict_version) {
     PyObject *dict = Py_TYPE(obj)->tp_dict;
-    if (!dict || tp_dict_version != __PYX_GET_DICT_VERSION(dict))
+    if (unlikely(!dict) || unlikely(tp_dict_version != __PYX_GET_DICT_VERSION(dict)))
         return 0;
     return obj_dict_version == __Pyx_get_object_dict_version(obj);
 }