gh-100239: replace BINARY_SUBSCR & family by BINARY_OP with oparg NB_SUBSCR (#129700)

Author: iritkatriel

Doc/library/dis.rst

@@ -703,15 +703,8 @@ not have to be) the original ``STACK[-2]``.
       STACK.append(lhs op rhs)
 
    .. versionadded:: 3.11
-
-
-.. opcode:: BINARY_SUBSCR
-
-   Implements::
-
-      key = STACK.pop()
-      container = STACK.pop()
-      STACK.append(container[key])
+   .. versionchanged:: 3.14
+      With oparg :``NB_SUBSCR``, implements binary subscript (replaces opcode ``BINARY_SUBSCR``)
 
 
 .. opcode:: STORE_SUBSCR

Doc/whatsnew/3.14.rst

@@ -1199,6 +1199,12 @@ Others
   :meth:`~object.__index__`. (Contributed by Mark Dickinson in :gh:`119743`.)
 
 
+CPython Bytecode Changes
+========================
+
+* Replaced the opcode ``BINARY_SUBSCR`` by :opcode:`BINARY_OP` with oparg ``NB_SUBSCR``.
+  (Contributed by Irit Katriel in :gh:`100239`.)
+
 Porting to Python 3.14
 ======================
 

Include/internal/pycore_code.h

@@ -338,8 +338,6 @@ extern void _Py_Specialize_StoreAttr(_PyStackRef owner, _Py_CODEUNIT *instr,
                                      PyObject *name);
 extern void _Py_Specialize_LoadGlobal(PyObject *globals, PyObject *builtins,
                                       _Py_CODEUNIT *instr, PyObject *name);
-extern void _Py_Specialize_BinarySubscr(_PyStackRef sub, _PyStackRef container,
-                                        _Py_CODEUNIT *instr);
 extern void _Py_Specialize_StoreSubscr(_PyStackRef container, _PyStackRef sub,
                                        _Py_CODEUNIT *instr);
 extern void _Py_Specialize_Call(_PyStackRef callable, _Py_CODEUNIT *instr,
@@ -586,6 +584,7 @@ typedef int (*binaryopguardfunc)(PyObject *lhs, PyObject *rhs);
 typedef PyObject *(*binaryopactionfunc)(PyObject *lhs, PyObject *rhs);
 
 typedef struct {
+    int oparg;
     binaryopguardfunc guard;
     binaryopactionfunc action;
 } _PyBinaryOpSpecializationDescr;

Include/internal/pycore_magic_number.h

@@ -268,6 +268,7 @@ Known values:
     Python 3.14a4 3613 (Add LOAD_CONST_MORTAL instruction)
     Python 3.14a5 3614 (Add BINARY_OP_EXTEND)
     Python 3.14a5 3615 (CALL_FUNCTION_EX always take a kwargs argument)
+    Python 3.14a5 3616 (Remove BINARY_SUBSCR and family. Make them BINARY_OPs)
 
     Python 3.15 will start with 3650
 
@@ -280,7 +281,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3615
+#define PYC_MAGIC_NUMBER 3616
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \