Revert "gh-100288: Specialise LOAD_ATTR_METHOD for managed dictionaries (GH-100289)" (#100468)

This reverts commit c3c7848.

Author: Fidget-Spinner

Include/internal/pycore_opcode.h

@@ -336,7 +336,6 @@ def pseudo_op(name, op, real_ops):
         # These will always push [unbound method, self] onto the stack.
         "LOAD_ATTR_METHOD_LAZY_DICT",
         "LOAD_ATTR_METHOD_NO_DICT",
-        "LOAD_ATTR_METHOD_MANAGED_DICT",
         "LOAD_ATTR_METHOD_WITH_DICT",
         "LOAD_ATTR_METHOD_WITH_VALUES",
     ],

Include/opcode.h

@@ -2717,31 +2717,6 @@ dummy_func(
             JUMPBY(INLINE_CACHE_ENTRIES_LOAD_ATTR);
         }
 
-        // error: LOAD_ATTR has irregular stack effect
-        inst(LOAD_ATTR_METHOD_MANAGED_DICT) {
-            assert(cframe.use_tracing == 0);
-            PyObject *self = TOP();
-            PyTypeObject *self_cls = Py_TYPE(self);
-            _PyLoadMethodCache *cache = (_PyLoadMethodCache *)next_instr;
-            uint32_t type_version = read_u32(cache->type_version);
-            assert(type_version != 0);
-            DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR)
-            assert(self_cls->tp_flags & Py_TPFLAGS_MANAGED_DICT);
-            PyDictOrValues dorv = *_PyObject_DictOrValuesPointer(self);
-            DEOPT_IF(_PyDictOrValues_IsValues(dorv), LOAD_ATTR);
-            PyObject *dict = _PyDictOrValues_GetDict(dorv);
-            PyDictKeysObject *keys = (dict == NULL) ? NULL : ((PyDictObject *)dict)->ma_keys;
-            // Note: cache->keys_version can be 0 when dict is NULL.
-            DEOPT_IF(keys != NULL && keys->dk_version != read_u32(cache->keys_version), LOAD_ATTR);
-            STAT_INC(LOAD_ATTR, hit);
-            PyObject *res = read_obj(cache->descr);
-            assert(res != NULL);
-            assert(_PyType_HasFeature(Py_TYPE(res), Py_TPFLAGS_METHOD_DESCRIPTOR));
-            SET_TOP(Py_NewRef(res));
-            PUSH(self);
-            JUMPBY(INLINE_CACHE_ENTRIES_LOAD_ATTR);
-        }
-
         // error: LOAD_ATTR has irregular stack effect
         inst(LOAD_ATTR_METHOD_WITH_DICT) {
             /* Can be either a managed dict, or a tp_dictoffset offset.*/

Lib/opcode.py

@@ -335,6 +335,7 @@ _PyCode_Quicken(PyCodeObject *code)
 #define SPEC_FAIL_ATTR_BUILTIN_CLASS_METHOD 22
 #define SPEC_FAIL_ATTR_CLASS_METHOD_OBJ 23
 #define SPEC_FAIL_ATTR_OBJECT_SLOT 24
+#define SPEC_FAIL_ATTR_HAS_MANAGED_DICT 25
 #define SPEC_FAIL_ATTR_INSTANCE_ATTRIBUTE 26
 #define SPEC_FAIL_ATTR_METACLASS_ATTRIBUTE 27
 #define SPEC_FAIL_ATTR_PROPERTY_NOT_PY_FUNCTION 28
@@ -1035,14 +1036,11 @@ PyObject *descr, DescriptorClassification kind)
     PyDictKeysObject *keys;
     if (owner_cls->tp_flags & Py_TPFLAGS_MANAGED_DICT) {
         PyDictOrValues dorv = *_PyObject_DictOrValuesPointer(owner);
+        keys = ((PyHeapTypeObject *)owner_cls)->ht_cached_keys;
         if (_PyDictOrValues_IsValues(dorv)) {
-            keys = ((PyHeapTypeObject *)owner_cls)->ht_cached_keys;
             dictkind = MANAGED_VALUES;
         }
         else {
-            PyDictObject *dict = (PyDictObject *)_PyDictOrValues_GetDict(dorv);
-            keys = dict != NULL ? dict->ma_keys : NULL;
-            // User has directly accessed __dict__.
             dictkind = MANAGED_DICT;
         }
     }
@@ -1069,7 +1067,7 @@ PyObject *descr, DescriptorClassification kind)
             }
         }
     }
-    if (dictkind == MANAGED_VALUES || dictkind == OFFSET_DICT || (dictkind == MANAGED_DICT && keys != NULL)) {
+    if (dictkind == MANAGED_VALUES || dictkind == OFFSET_DICT) {
         Py_ssize_t index = _PyDictKeys_StringLookup(keys, name);
         if (index != DKIX_EMPTY) {
             SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_SHADOWED);
@@ -1090,11 +1088,8 @@ PyObject *descr, DescriptorClassification kind)
             _py_set_opcode(instr, LOAD_ATTR_METHOD_WITH_VALUES);
             break;
         case MANAGED_DICT:
-            if (keys == NULL) {
-                write_u32(cache->keys_version, 0);
-            }
-            _py_set_opcode(instr, LOAD_ATTR_METHOD_MANAGED_DICT);
-            break;
+            SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_HAS_MANAGED_DICT);
+            goto fail;
         case OFFSET_DICT:
             assert(owner_cls->tp_dictoffset > 0 && owner_cls->tp_dictoffset <= INT16_MAX);
             _py_set_opcode(instr, LOAD_ATTR_METHOD_WITH_DICT);