python · markshannon · Aug 17, 2021 · Aug 6, 2021 · Aug 6, 2021 · Aug 7, 2021
diff --git a/Include/internal/pycore_code.h b/Include/internal/pycore_code.h
@@ -30,6 +30,11 @@ typedef struct {
     uint32_t builtin_keys_version;
 } _PyLoadGlobalCache;
 
+typedef struct {
+    /* Borrowed ref in LOAD_METHOD */
+    PyObject *obj;
+} _PyObjectCache;
+
 /* Add specialized versions of entries to this union.
  *
  * Do not break the invariant: sizeof(SpecializedCacheEntry) == 8
@@ -45,6 +50,7 @@ typedef union {
     _PyAdaptiveEntry adaptive;
     _PyAttrCache attr;
     _PyLoadGlobalCache load_global;
+    _PyObjectCache obj;
 } SpecializedCacheEntry;
 
 #define INSTRUCTIONS_PER_ENTRY (sizeof(SpecializedCacheEntry)/sizeof(_Py_CODEUNIT))
@@ -299,6 +305,7 @@ cache_backoff(_PyAdaptiveEntry *entry) {
 int _Py_Specialize_LoadAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache);
 int _Py_Specialize_StoreAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache);
 int _Py_Specialize_LoadGlobal(PyObject *globals, PyObject *builtins, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache);
+int _Py_Specialize_LoadMethod(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache);
 int _Py_Specialize_BinarySubscr(PyObject *sub, PyObject *container, _Py_CODEUNIT *instr);
 
 #define PRINT_SPECIALIZATION_STATS 0

diff --git a/Include/opcode.h b/Include/opcode.h
diff --git a/Lib/opcode.py b/Lib/opcode.py
@@ -233,6 +233,10 @@ def jabs_op(name, op):
     "LOAD_GLOBAL_ADAPTIVE",
     "LOAD_GLOBAL_MODULE",
     "LOAD_GLOBAL_BUILTIN",
+    "LOAD_METHOD_ADAPTIVE",
+    "LOAD_METHOD_CACHED",
+    "LOAD_METHOD_CLASS",
+    "LOAD_METHOD_MODULE",
     "STORE_ATTR_ADAPTIVE",
     "STORE_ATTR_SPLIT_KEYS",
     "STORE_ATTR_SLOT",

diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-08-11-20-45-02.bpo-44889.2T3nTn.rst b/Misc/NEWS.d/next/Core and Builtins/2021-08-11-20-45-02.bpo-44889.2T3nTn.rst
@@ -0,0 +1,8 @@
+Initial implementation of adaptive specialization of ``LOAD_METHOD``. The
+following specialized forms were added:
+
+* ``LOAD_METHOD_CACHED``
+
+* ``LOAD_METHOD_MODULE``
+
+* ``LOAD_METHOD_CLASS``
@@ -1439,6 +1439,27 @@ eval_frame_handle_pending(PyThreadState *tstate)
 #define BUILTINS() frame->f_builtins
 #define LOCALS() frame->f_locals
 
+/* Shared opcode macros */
+
+// shared by LOAD_ATTR_MODULE and LOAD_METHOD_MODULE
+#define LOAD_MODULE_ATTR_OR_METHOD(attr_or_method) \
+    SpecializedCacheEntry *caches = GET_CACHE(); \
+    _PyAdaptiveEntry *cache0 = &caches[0].adaptive; \
+    _PyAttrCache *cache1 = &caches[-1].attr; \
+    DEOPT_IF(!PyModule_CheckExact(owner), LOAD_##attr_or_method); \
+    PyDictObject *dict = (PyDictObject *)((PyModuleObject *)owner)->md_dict; \
+    assert(dict != NULL); \
+    DEOPT_IF(dict->ma_keys->dk_version != cache1->dk_version_or_hint, \
+        LOAD_##attr_or_method); \
+    assert(dict->ma_keys->dk_kind == DICT_KEYS_UNICODE); \
+    assert(cache0->index < dict->ma_keys->dk_nentries); \
+    PyDictKeyEntry *ep = DK_ENTRIES(dict->ma_keys) + cache0->index; \
+    res = ep->me_value; \
+    DEOPT_IF(res == NULL, LOAD_##attr_or_method); \
+    STAT_INC(LOAD_##attr_or_method, hit); \
+    record_cache_hit(cache0); \
+    Py_INCREF(res);
+
 static int
 trace_function_entry(PyThreadState *tstate, InterpreterFrame *frame)
 {
@@ -3511,23 +3532,10 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
 
         TARGET(LOAD_ATTR_MODULE): {
             assert(cframe.use_tracing == 0);
+            // shared with LOAD_METHOD_MODULE
             PyObject *owner = TOP();
             PyObject *res;
-            SpecializedCacheEntry *caches = GET_CACHE();
-            _PyAdaptiveEntry *cache0 = &caches[0].adaptive;
-            _PyAttrCache *cache1 = &caches[-1].attr;
-            DEOPT_IF(!PyModule_CheckExact(owner), LOAD_ATTR);
-            PyDictObject *dict = (PyDictObject *)((PyModuleObject *)owner)->md_dict;
-            assert(dict != NULL);
-            DEOPT_IF(dict->ma_keys->dk_version != cache1->dk_version_or_hint, LOAD_ATTR);
-            assert(dict->ma_keys->dk_kind == DICT_KEYS_UNICODE);
-            assert(cache0->index < dict->ma_keys->dk_nentries);
-            PyDictKeyEntry *ep = DK_ENTRIES(dict->ma_keys) + cache0->index;
-            res = ep->me_value;
-            DEOPT_IF(res == NULL, LOAD_ATTR);
-            STAT_INC(LOAD_ATTR, hit);
-            record_cache_hit(cache0);
-            Py_INCREF(res);
+            LOAD_MODULE_ATTR_OR_METHOD(ATTR);
             SET_TOP(res);
             Py_DECREF(owner);
             DISPATCH();
@@ -4282,6 +4290,8 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
         }
 
         TARGET(LOAD_METHOD): {
+            PREDICTED(LOAD_METHOD);
+            STAT_INC(LOAD_METHOD, unquickened);
             /* Designed to work in tandem with CALL_METHOD. */
             PyObject *name = GETITEM(names, oparg);
             PyObject *obj = TOP();
@@ -4318,6 +4328,107 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
             DISPATCH();
         }
 
+        TARGET(LOAD_METHOD_ADAPTIVE): {
+            assert(cframe.use_tracing == 0);
+            SpecializedCacheEntry *cache = GET_CACHE();
+            if (cache->adaptive.counter == 0) {
+                PyObject *owner = TOP();
+                PyObject *name = GETITEM(names, cache->adaptive.original_oparg);
+                next_instr--;
+                if (_Py_Specialize_LoadMethod(owner, next_instr, name, cache) < 0) {
+                    goto error;
+                }
+                DISPATCH();
+            }
+            else {
+                STAT_INC(LOAD_METHOD, deferred);
+                cache->adaptive.counter--;
+                oparg = cache->adaptive.original_oparg;
+                STAT_DEC(LOAD_METHOD, unquickened);
+                JUMP_TO_INSTRUCTION(LOAD_METHOD);
+            }            
+        }
+
+        TARGET(LOAD_METHOD_CACHED): {
+            /* LOAD_METHOD, with cached method object */
+            assert(cframe.use_tracing == 0);
+            PyObject *self = TOP();
+            PyTypeObject *self_cls = Py_TYPE(self);
+            SpecializedCacheEntry *caches = GET_CACHE();
+            _PyAdaptiveEntry *cache0 = &caches[0].adaptive;
+            _PyAttrCache *cache1 = &caches[-1].attr;
+            _PyObjectCache *cache2 = &caches[-2].obj;
+
+            DEOPT_IF(self_cls->tp_version_tag != cache1->tp_version, LOAD_METHOD);
+            assert(cache1->dk_version_or_hint != 0);
+            assert(cache1->tp_version != 0);
+            assert(self_cls->tp_dictoffset >= 0);
+            assert(Py_TYPE(self_cls)->tp_dictoffset > 0);
+
+            // inline version of _PyObject_GetDictPtr for offset >= 0
+            PyObject *dict = self_cls->tp_dictoffset != 0 ?
+                *(PyObject **) ((char *)self + self_cls->tp_dictoffset) : NULL;
+
+            // Ensure self.__dict__ didn't modify keys.
+            // Don't care if self has no dict, it could be builtin or __slots__.
+            DEOPT_IF(dict != NULL &&
+                ((PyDictObject *)dict)->ma_keys->dk_version !=
+                cache1->dk_version_or_hint, LOAD_METHOD);
+
+            STAT_INC(LOAD_METHOD, hit);
+            record_cache_hit(cache0);
+            PyObject *res = cache2->obj;
+            assert(res != NULL);
+            assert(_PyType_HasFeature(Py_TYPE(res), Py_TPFLAGS_METHOD_DESCRIPTOR));
+            Py_INCREF(res);
+            SET_TOP(res);
+            PUSH(self);
+            DISPATCH();
+        }
+
+        TARGET(LOAD_METHOD_MODULE): {
+            assert(cframe.use_tracing == 0);
+            PyObject *owner = TOP();
+            PyObject *res;
+            LOAD_MODULE_ATTR_OR_METHOD(METHOD);
+            SET_TOP(NULL);
+            Py_DECREF(owner);
+            PUSH(res);
+            DISPATCH();
+        }
+
+        TARGET(LOAD_METHOD_CLASS): {
+            /* LOAD_METHOD, for class methods */
+            assert(cframe.use_tracing == 0);
+            SpecializedCacheEntry *caches = GET_CACHE();
+            _PyAdaptiveEntry *cache0 = &caches[0].adaptive;
+            _PyAttrCache *cache1 = &caches[-1].attr;
+            _PyObjectCache *cache2 = &caches[-2].obj;
+
+            PyObject *cls = TOP();
+            PyTypeObject *cls_type = Py_TYPE(cls);
+            assert(cls_type->tp_dictoffset > 0);
+            PyObject *dict = *(PyObject **) ((char *)cls + cls_type->tp_dictoffset);
+            // Don't care if no dict -- tp_version_tag should catch anything wrong.
+            DEOPT_IF(dict != NULL && ((PyDictObject *)dict)->ma_keys->dk_version !=
+                cache1->dk_version_or_hint, LOAD_METHOD);
+            DEOPT_IF(((PyTypeObject *)cls)->tp_version_tag != cache1->tp_version,
+                LOAD_METHOD);
+            assert(cache1->dk_version_or_hint != 0);
+            assert(cache1->tp_version != 0);
+
+            STAT_INC(LOAD_METHOD, hit);
+            record_cache_hit(cache0);
+            PyObject *res = cache2->obj;
+            assert(res != NULL);
+            assert(_PyType_HasFeature(Py_TYPE(res), Py_TPFLAGS_METHOD_DESCRIPTOR));
+            Py_INCREF(res);
+            SET_TOP(NULL);
+            Py_DECREF(cls);
+            PUSH(res);
+            DISPATCH();
+        }
+
         TARGET(CALL_METHOD): {
             /* Designed to work in tamdem with LOAD_METHOD. */
             PyObject **sp, *res;
@@ -4648,6 +4759,7 @@ opname ## _miss: \
 MISS_WITH_CACHE(LOAD_ATTR)
 MISS_WITH_CACHE(STORE_ATTR)
 MISS_WITH_CACHE(LOAD_GLOBAL)
+MISS_WITH_CACHE(LOAD_METHOD)
 MISS_WITH_OPARG_COUNTER(BINARY_SUBSCR)
 
 binary_subscr_dict_error:

diff --git a/Python/opcode_targets.h b/Python/opcode_targets.h