GH-100288: Specialize LOAD_ATTR for simple class attributes. (#105990)

* Add two more specializations of LOAD_ATTR.

Author: markshannon

Include/internal/pycore_opcode.h

@@ -63,6 +63,8 @@
         "LOAD_ATTR_METHOD_WITH_VALUES",
         "LOAD_ATTR_METHOD_NO_DICT",
         "LOAD_ATTR_METHOD_LAZY_DICT",
+        "LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES",
+        "LOAD_ATTR_NONDESCRIPTOR_NO_DICT",
     ],
     "COMPARE_OP": [
         "COMPARE_OP_FLOAT",

Include/opcode.h

@@ -0,0 +1,3 @@
+Specialize :opcode:`LOAD_ATTR` for non-descriptors on the class. Adds
+:opcode:`LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES` and :opcode
+`LOAD_ATTR_NONDESCRIPTOR_NO_DICT`.

Lib/_opcode_metadata.py

@@ -1809,6 +1809,8 @@ dummy_func(
             LOAD_ATTR_METHOD_WITH_VALUES,
             LOAD_ATTR_METHOD_NO_DICT,
             LOAD_ATTR_METHOD_LAZY_DICT,
+            LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES,
+            LOAD_ATTR_NONDESCRIPTOR_NO_DICT,
         };
 
         inst(LOAD_ATTR, (unused/9, owner -- res2 if (oparg & 1), res)) {
@@ -2657,7 +2659,8 @@ dummy_func(
             exc_info->exc_value = Py_NewRef(new_exc);
         }
 
-        inst(LOAD_ATTR_METHOD_WITH_VALUES, (unused/1, type_version/2, keys_version/2, descr/4, self -- res2 if (oparg & 1), res)) {
+        inst(LOAD_ATTR_METHOD_WITH_VALUES, (unused/1, type_version/2, keys_version/2, descr/4, self -- res2 if (1), res)) {
+            assert(oparg & 1);
             /* Cached method object */
             PyTypeObject *self_cls = Py_TYPE(self);
             assert(type_version != 0);
@@ -2673,10 +2676,10 @@ dummy_func(
             res2 = Py_NewRef(descr);
             assert(_PyType_HasFeature(Py_TYPE(res2), Py_TPFLAGS_METHOD_DESCRIPTOR));
             res = self;
-            assert(oparg & 1);
         }
 
-        inst(LOAD_ATTR_METHOD_NO_DICT, (unused/1, type_version/2, unused/2, descr/4, self -- res2 if (oparg & 1), res)) {
+        inst(LOAD_ATTR_METHOD_NO_DICT, (unused/1, type_version/2, unused/2, descr/4, self -- res2 if (1), res)) {
+            assert(oparg & 1);
             PyTypeObject *self_cls = Py_TYPE(self);
             DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR);
             assert(self_cls->tp_dictoffset == 0);
@@ -2685,10 +2688,39 @@ dummy_func(
             assert(_PyType_HasFeature(Py_TYPE(descr), Py_TPFLAGS_METHOD_DESCRIPTOR));
             res2 = Py_NewRef(descr);
             res = self;
-            assert(oparg & 1);
         }
 
-        inst(LOAD_ATTR_METHOD_LAZY_DICT, (unused/1, type_version/2, unused/2, descr/4, self -- res2 if (oparg & 1), res)) {
+        inst(LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES, (unused/1, type_version/2, keys_version/2, descr/4, self -- res2 if (0), res)) {
+            assert((oparg & 1) == 0);
+            PyTypeObject *self_cls = Py_TYPE(self);
+            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);
+            PyHeapTypeObject *self_heap_type = (PyHeapTypeObject *)self_cls;
+            DEOPT_IF(self_heap_type->ht_cached_keys->dk_version !=
+                     keys_version, LOAD_ATTR);
+            STAT_INC(LOAD_ATTR, hit);
+            assert(descr != NULL);
+            DECREF_INPUTS();
+            res = Py_NewRef(descr);
+        }
+
+        inst(LOAD_ATTR_NONDESCRIPTOR_NO_DICT, (unused/1, type_version/2, unused/2, descr/4, self -- res2 if (0), res)) {
+            assert((oparg & 1) == 0);
+            PyTypeObject *self_cls = Py_TYPE(self);
+            assert(type_version != 0);
+            DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR);
+            assert(self_cls->tp_dictoffset == 0);
+            STAT_INC(LOAD_ATTR, hit);
+            assert(descr != NULL);
+            DECREF_INPUTS();
+            res = Py_NewRef(descr);
+        }
+
+        inst(LOAD_ATTR_METHOD_LAZY_DICT, (unused/1, type_version/2, unused/2, descr/4, self -- res2 if (1), res)) {
+            assert(oparg & 1);
             PyTypeObject *self_cls = Py_TYPE(self);
             DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR);
             Py_ssize_t dictoffset = self_cls->tp_dictoffset;
@@ -2701,7 +2733,6 @@ dummy_func(
             assert(_PyType_HasFeature(Py_TYPE(descr), Py_TPFLAGS_METHOD_DESCRIPTOR));
             res2 = Py_NewRef(descr);
             res = self;
-            assert(oparg & 1);
         }
 
         inst(KW_NAMES, (--)) {