bpo-46841: Use inline cache for BINARY_SUBSCR. (GH-31618)

Include/cpython/object.h

@@ -229,6 +229,13 @@ struct _typeobject {
     vectorcallfunc tp_vectorcall;
 };
 
+/* This struct is used by the specializer
+ * It should should be treated as an opaque blob
+ * by code other than the specializer and interpreter. */
+struct _specialization_cache {
+    PyObject *getitem;
+};
+
 /* The *real* layout of a type object when allocated on the heap */
 typedef struct _heaptypeobject {
     /* Note: there's a dependency on the order of these members
@@ -247,6 +254,7 @@ typedef struct _heaptypeobject {
     struct _dictkeysobject *ht_cached_keys;
     PyObject *ht_module;
     char *_ht_tpname;  // Storage for "tp_name"; see PyType_FromModuleAndSpec
+    struct _specialization_cache _spec_cache; // For use by the specializer.
     /* here are optional user slots, followed by the members. */
 } PyHeapTypeObject;
 

Include/internal/pycore_code.h

@@ -92,6 +92,15 @@ typedef struct {
 
 #define INLINE_CACHE_ENTRIES_COMPARE_OP CACHE_ENTRIES(_PyCompareOpCache)
 
+typedef struct {
+    _Py_CODEUNIT counter;
+    _Py_CODEUNIT type_version;
+    _Py_CODEUNIT _t1;
+    _Py_CODEUNIT func_version;
+} _PyBinarySubscrCache;
+
+#define INLINE_CACHE_ENTRIES_BINARY_SUBSCR CACHE_ENTRIES(_PyBinarySubscrCache)
+
 /* Maximum size of code to quicken, in code units. */
 #define MAX_SIZE_TO_QUICKEN 5000
 
@@ -323,7 +332,7 @@ extern int _Py_Specialize_LoadAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObjec
 extern int _Py_Specialize_StoreAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache);
 extern int _Py_Specialize_LoadGlobal(PyObject *globals, PyObject *builtins, _Py_CODEUNIT *instr, PyObject *name);
 extern int _Py_Specialize_LoadMethod(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache);
-extern int _Py_Specialize_BinarySubscr(PyObject *sub, PyObject *container, _Py_CODEUNIT *instr, SpecializedCacheEntry *cache);
+extern int _Py_Specialize_BinarySubscr(PyObject *sub, PyObject *container, _Py_CODEUNIT *instr);
 extern int _Py_Specialize_StoreSubscr(PyObject *container, PyObject *sub, _Py_CODEUNIT *instr);
 extern int _Py_Specialize_Call(PyObject *callable, _Py_CODEUNIT *instr, int nargs,
     PyObject *kwnames, SpecializedCacheEntry *cache);

Include/opcode.h

@@ -211,6 +211,7 @@ static const uint32_t _PyOpcode_Jump[8] = {
 };
 
 const uint8_t _PyOpcode_InlineCacheEntries[256] = {
+    [BINARY_SUBSCR] = 4,
     [UNPACK_SEQUENCE] = 1,
     [COMPARE_OP] = 2,
     [LOAD_GLOBAL] = 5,