GH-105848: Get rid of KW_NAMES

Doc/library/dis.rst

@@ -58,7 +58,7 @@ the following command can be used to display the disassembly of
    <BLANKLINE>
      3           2 LOAD_GLOBAL              1 (NULL + len)
                 12 LOAD_FAST                0 (alist)
-                14 CALL                     1
+                14 CALL                     2 (1)
                 22 RETURN_VALUE
 
 (The "2" is a line number).
@@ -1361,22 +1361,23 @@ iterations of the loop.
 
 .. opcode:: CALL (argc)
 
-   Calls a callable object with the number of arguments specified by ``argc``,
-   including the named arguments specified by the preceding
-   :opcode:`KW_NAMES`, if any.
+   Calls a callable object with the number of arguments specified by ``argc >> 1``,
+   including the named arguments, if ``argc & 1``.
    On the stack are (in ascending order), either:
 
    * NULL
    * The callable
    * The positional arguments
-   * The named arguments
+   * The named arguments (if ``argc & 1``)
+   * A tuple of keyword names (if ``argc & 1``)
 
    or:
 
    * The callable
    * ``self``
    * The remaining positional arguments
-   * The named arguments
+   * The named arguments (if ``argc & 1``)
+   * A tuple of keyword names (if ``argc & 1``)
 
    ``argc`` is the total of the positional and named arguments, excluding
    ``self`` when a ``NULL`` is not present.
@@ -1387,6 +1388,11 @@ iterations of the loop.
 
    .. versionadded:: 3.11
 
+   .. versionchanged:: 3.13
+      Keyword names are now found to the stack, and the presence of keyword
+      arguments is indicated by the low bit of the oparg (rather than a separate
+      ``KW_NAMES`` instruction).
+
 
 .. opcode:: CALL_FUNCTION_EX (flags)
 
@@ -1412,15 +1418,6 @@ iterations of the loop.
    .. versionadded:: 3.11
 
 
-.. opcode:: KW_NAMES (consti)
-
-   Prefixes :opcode:`CALL`.
-   Stores a reference to ``co_consts[consti]`` into an internal variable
-   for use by :opcode:`CALL`. ``co_consts[consti]`` must be a tuple of strings.
-
-   .. versionadded:: 3.11
-
-
 .. opcode:: MAKE_FUNCTION
 
    Pushes a new function object on the stack built from the code object at ``STACK[1]``.

Lib/dis.py

@@ -44,6 +44,7 @@
 LOAD_FAST_LOAD_FAST = opmap['LOAD_FAST_LOAD_FAST']
 STORE_FAST_LOAD_FAST = opmap['STORE_FAST_LOAD_FAST']
 STORE_FAST_STORE_FAST = opmap['STORE_FAST_STORE_FAST']
+CALL = opmap['CALL']
 
 CACHE = opmap["CACHE"]
 
@@ -586,6 +587,12 @@ def _get_instructions_bytes(code, varname_from_oparg=None,
                 argrepr = _intrinsic_1_descs[arg]
             elif deop == CALL_INTRINSIC_2:
                 argrepr = _intrinsic_2_descs[arg]
+            elif deop == CALL:
+                argval = arg >> 1
+                if arg & 1:
+                    argrepr = f"{argval} + keywords"
+                else:
+                    argrepr = repr(argval)
         yield Instruction(_all_opname[op], op,
                           arg, argval, argrepr,
                           offset, start_offset, starts_line, is_jump_target, positions)

Lib/importlib/_bootstrap_external.py

@@ -450,6 +450,7 @@ def _write_atomic(path, data, mode=0o666):
 #     Python 3.13a1 3552 (Remove LOAD_FAST__LOAD_CONST and LOAD_CONST__LOAD_FAST)
 #     Python 3.13a1 3553 (Add SET_FUNCTION_ATTRIBUTE)
 #     Python 3.13a1 3554 (more efficient bytecodes for f-strings)
+#     Python 3.13a1 3555 (Remove KW_NAMES)
 
 #     Python 3.14 will start with 3600
 
@@ -466,7 +467,7 @@ def _write_atomic(path, data, mode=0o666):
 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
 # in PC/launcher.c must also be updated.
 
-MAGIC_NUMBER = (3554).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3555).to_bytes(2, 'little') + b'\r\n'
 
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 

Lib/opcode.py

@@ -229,8 +229,7 @@ def pseudo_op(name, op, real_ops):
 def_op('STORE_FAST_LOAD_FAST', 169)
 def_op('STORE_FAST_STORE_FAST', 170)
 def_op('CALL', 171)
-def_op('KW_NAMES', 172)
-hasconst.append(172)
+
 def_op('CALL_INTRINSIC_1', 173)
 def_op('CALL_INTRINSIC_2', 174)
 

Lib/test/test_compiler_codegen.py

@@ -43,7 +43,7 @@ def test_for_loop(self):
             ('PUSH_NULL', None, 2),
             ('LOAD_NAME', 2, 2),
             ('LOAD_NAME', 1, 2),
-            ('CALL', 1, 2),
+            ('CALL', (1 << 1) | 0, 2),
             ('POP_TOP', None),
             ('JUMP', loop_lbl),
             exit_lbl,