python · brandtbucher · Aug 9, 2023 · Aug 5, 2023 · Aug 5, 2023 · Aug 5, 2023
diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst
@@ -56,7 +56,7 @@ the following command can be used to display the disassembly of
    >>> dis.dis(myfunc)
      2           0 RESUME                   0
    <BLANKLINE>
-     3           2 LOAD_GLOBAL              1 (NULL + len)
+     3           2 LOAD_GLOBAL              1 (len + NULL)
                 12 LOAD_FAST                0 (alist)
                 14 CALL                     1
                 22 RETURN_VALUE

diff --git a/Include/internal/pycore_opcode_metadata.h b/Include/internal/pycore_opcode_metadata.h
diff --git a/Lib/dis.py b/Lib/dis.py
@@ -552,15 +552,15 @@ def _get_instructions_bytes(code, varname_from_oparg=None,
                 if deop == LOAD_GLOBAL:
                     argval, argrepr = _get_name_info(arg//2, get_name)
                     if (arg & 1) and argrepr:
-                        argrepr = "NULL + " + argrepr
+                        argrepr = f"{argrepr} + NULL"
                 elif deop == LOAD_ATTR:
                     argval, argrepr = _get_name_info(arg//2, get_name)
                     if (arg & 1) and argrepr:
-                        argrepr = "NULL|self + " + argrepr
+                        argrepr = f"{argrepr} + NULL|self"
                 elif deop == LOAD_SUPER_ATTR:
                     argval, argrepr = _get_name_info(arg//4, get_name)
                     if (arg & 1) and argrepr:
-                        argrepr = "NULL|self + " + argrepr
+                        argrepr = f"{argrepr} + NULL|self"
                 else:
                     argval, argrepr = _get_name_info(arg, get_name)
             elif deop in hasjabs:

@@ -453,6 +453,7 @@ def _write_atomic(path, data, mode=0o666):
 #     Python 3.13a1 3555 (generate specialized opcodes metadata from bytecodes.c)
 #     Python 3.13a1 3556 (Convert LOAD_CLOSURE to a pseudo-op)
 #     Python 3.13a1 3557 (Make the conversion to boolean in jumps explicit)
+#     Python 3.13a1 3558 (Reorder the stack items for CALL)
 
 #     Python 3.14 will start with 3600
 
@@ -469,7 +470,7 @@ 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 = (3557).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3558).to_bytes(2, 'little') + b'\r\n'
 
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 

diff --git a/Lib/test/test_compiler_assemble.py b/Lib/test/test_compiler_assemble.py
@@ -94,12 +94,12 @@ def inner():
 
         instructions = [
             ('RESUME', 0,),
-            ('PUSH_NULL', 0, 1),
             ('LOAD_CLOSURE', 0, 1),
             ('BUILD_TUPLE', 1, 1),
             ('LOAD_CONST', 1, 1),
             ('MAKE_FUNCTION', 0, 2),
             ('SET_FUNCTION_ATTRIBUTE', 8, 2),
+            ('PUSH_NULL', 0, 1),
             ('CALL', 0, 2),                     # (lambda: x)()
             ('LOAD_CONST', 2, 2),               # 2
             ('BINARY_OP', 6, 2),                # %

diff --git a/Lib/test/test_compiler_codegen.py b/Lib/test/test_compiler_codegen.py
@@ -41,8 +41,8 @@ def test_for_loop(self):
             loop_lbl := self.Label(),
             ('FOR_ITER', exit_lbl := self.Label(), 1),
             ('STORE_NAME', 1, 1),
-            ('PUSH_NULL', None, 2),
             ('LOAD_NAME', 2, 2),
+            ('PUSH_NULL', None, 2),
             ('LOAD_NAME', 1, 2),
             ('CALL', 1, 2),
             ('POP_TOP', None),

diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-08-05-09-06-56.gh-issue-105848.Drc-1-.rst b/Misc/NEWS.d/next/Core and Builtins/2023-08-05-09-06-56.gh-issue-105848.Drc-1-.rst
@@ -0,0 +1,3 @@
+Modify the bytecode so that the actual callable for a :opcode:`CALL` is at a
+consistent position on the stack (regardless of whether or not
+bound-method-calling optimizations are active).
diff --git a/Objects/exception_handling_notes.txt b/Objects/exception_handling_notes.txt
@@ -47,7 +47,7 @@ a table to determine where to jump to when an exception is raised.
 
   2           2 NOP
 
-  3           4 LOAD_GLOBAL              1 (NULL + g)
+  3           4 LOAD_GLOBAL              1 (g + NULL)
              16 LOAD_CONST               1 (0)
              18 PRECALL                  1
              22 CALL                     1