diff --git a/Doc/c-api/abstract.rst b/Doc/c-api/abstract.rst
index 1823f9d70c79f3..f5df09fa7fd786 100644
--- a/Doc/c-api/abstract.rst
+++ b/Doc/c-api/abstract.rst
@@ -24,4 +24,3 @@ but whose items have not been set to some non-\ ``NULL`` value yet.
    mapping.rst
    iter.rst
    buffer.rst
-   objbuffer.rst
diff --git a/Doc/c-api/marshal.rst b/Doc/c-api/marshal.rst
index 8e25968c6909fd..489f1580a414b2 100644
--- a/Doc/c-api/marshal.rst
+++ b/Doc/c-api/marshal.rst
@@ -25,12 +25,16 @@ unmarshalling.  Version 2 uses a binary format for floating point numbers.
    the least-significant 32 bits of *value*; regardless of the size of the
    native :c:expr:`long` type.  *version* indicates the file format.
 
+   This function can fail, in which case it sets the error indicator.
+   Use :c:func:`PyErr_Occurred` to check for that.
 
 .. c:function:: void PyMarshal_WriteObjectToFile(PyObject *value, FILE *file, int version)
 
    Marshal a Python object, *value*, to *file*.
    *version* indicates the file format.
 
+   This function can fail, in which case it sets the error indicator.
+   Use :c:func:`PyErr_Occurred` to check for that.
 
 .. c:function:: PyObject* PyMarshal_WriteObjectToString(PyObject *value, int version)
 
diff --git a/Doc/c-api/objbuffer.rst b/Doc/c-api/objbuffer.rst
deleted file mode 100644
index 6b82a642d7ee42..00000000000000
--- a/Doc/c-api/objbuffer.rst
+++ /dev/null
@@ -1,55 +0,0 @@
-.. highlight:: c
-
-Old Buffer Protocol
--------------------
-
-.. deprecated:: 3.0
-
-These functions were part of the "old buffer protocol" API in Python 2.
-In Python 3, this protocol doesn't exist anymore but the functions are still
-exposed to ease porting 2.x code.  They act as a compatibility wrapper
-around the :ref:`new buffer protocol <bufferobjects>`, but they don't give
-you control over the lifetime of the resources acquired when a buffer is
-exported.
-
-Therefore, it is recommended that you call :c:func:`PyObject_GetBuffer`
-(or the ``y*`` or ``w*`` :ref:`format codes <arg-parsing>` with the
-:c:func:`PyArg_ParseTuple` family of functions) to get a buffer view over
-an object, and :c:func:`PyBuffer_Release` when the buffer view can be released.
-
-
-.. c:function:: int PyObject_AsCharBuffer(PyObject *obj, const char **buffer, Py_ssize_t *buffer_len)
-
-   Returns a pointer to a read-only memory location usable as character-based
-   input.  The *obj* argument must support the single-segment character buffer
-   interface.  On success, returns ``0``, sets *buffer* to the memory location
-   and *buffer_len* to the buffer length.  Returns ``-1`` and sets a
-   :exc:`TypeError` on error.
-
-
-.. c:function:: int PyObject_AsReadBuffer(PyObject *obj, const void **buffer, Py_ssize_t *buffer_len)
-
-   Returns a pointer to a read-only memory location containing arbitrary data.
-   The *obj* argument must support the single-segment readable buffer
-   interface.  On success, returns ``0``, sets *buffer* to the memory location
-   and *buffer_len* to the buffer length.  Returns ``-1`` and sets a
-   :exc:`TypeError` on error.
-
-
-.. c:function:: int PyObject_CheckReadBuffer(PyObject *o)
-
-   Returns ``1`` if *o* supports the single-segment readable buffer interface.
-   Otherwise returns ``0``.  This function always succeeds.
-
-   Note that this function tries to get and release a buffer, and exceptions
-   which occur while calling corresponding functions will get suppressed.
-   To get error reporting use :c:func:`PyObject_GetBuffer()` instead.
-
-
-.. c:function:: int PyObject_AsWriteBuffer(PyObject *obj, void **buffer, Py_ssize_t *buffer_len)
-
-   Returns a pointer to a writable memory location.  The *obj* argument must
-   support the single-segment, character buffer interface.  On success,
-   returns ``0``, sets *buffer* to the memory location and *buffer_len* to the
-   buffer length.  Returns ``-1`` and sets a :exc:`TypeError` on error.
-
diff --git a/Doc/data/refcounts.dat b/Doc/data/refcounts.dat
index 65ffb96d5c8265..f5628abb90443c 100644
--- a/Doc/data/refcounts.dat
+++ b/Doc/data/refcounts.dat
@@ -1578,21 +1578,6 @@ PyOS_FSPath:PyObject*:path:0:
 PyObject_ASCII:PyObject*::+1:
 PyObject_ASCII:PyObject*:o:0:
 
-PyObject_AsCharBuffer:int:::
-PyObject_AsCharBuffer:PyObject*:obj:0:
-PyObject_AsCharBuffer:const char**:buffer::
-PyObject_AsCharBuffer:Py_ssize_t*:buffer_len::
-
-PyObject_AsReadBuffer:int:::
-PyObject_AsReadBuffer:PyObject*:obj:0:
-PyObject_AsReadBuffer:const void**:buffer::
-PyObject_AsReadBuffer:Py_ssize_t*:buffer_len::
-
-PyObject_AsWriteBuffer:int:::
-PyObject_AsWriteBuffer:PyObject*:obj:0:
-PyObject_AsWriteBuffer:void**:buffer::
-PyObject_AsWriteBuffer:Py_ssize_t*:buffer_len::
-
 PyObject_Bytes:PyObject*::+1:
 PyObject_Bytes:PyObject*:o:0:
 
diff --git a/Doc/data/stable_abi.dat b/Doc/data/stable_abi.dat
index 767025b76f8b11..80806aedfcdbd5 100644
--- a/Doc/data/stable_abi.dat
+++ b/Doc/data/stable_abi.dat
@@ -476,10 +476,7 @@ type,PyObject,3.2,,members
 member,PyObject.ob_refcnt,3.2,,
 member,PyObject.ob_type,3.2,,
 function,PyObject_ASCII,3.2,,
-function,PyObject_AsCharBuffer,3.2,,
 function,PyObject_AsFileDescriptor,3.2,,
-function,PyObject_AsReadBuffer,3.2,,
-function,PyObject_AsWriteBuffer,3.2,,
 function,PyObject_Bytes,3.2,,
 function,PyObject_Call,3.2,,
 function,PyObject_CallFunction,3.2,,
@@ -490,7 +487,6 @@ function,PyObject_CallNoArgs,3.10,,
 function,PyObject_CallObject,3.2,,
 function,PyObject_Calloc,3.7,,
 function,PyObject_CheckBuffer,3.11,,
-function,PyObject_CheckReadBuffer,3.2,,
 function,PyObject_ClearWeakRefs,3.2,,
 function,PyObject_CopyData,3.11,,
 function,PyObject_DelItem,3.2,,
diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index e4b6e3b6ff99b3..04ac34e09264b7 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -395,6 +395,42 @@ Removed
 
   (Contributed by Victor Stinner in :gh:`105107`.)
 
+* Remove old buffer protocols deprecated in Python 3.0. Use :ref:`bufferobjects` instead.
+
+   * :c:func:`!PyObject_CheckReadBuffer`: Use :c:func:`PyObject_CheckBuffer` to
+     test if the object supports the buffer protocol.
+     Note that :c:func:`PyObject_CheckBuffer` doesn't guarantee that
+     :c:func:`PyObject_GetBuffer` will succeed.
+     To test if the object is actually readable, see the next example
+     of :c:func:`PyObject_GetBuffer`.
+
+   * :c:func:`!PyObject_AsCharBuffer`, :c:func:`!PyObject_AsReadBuffer`:
+     :c:func:`PyObject_GetBuffer` and :c:func:`PyBuffer_Release` instead:
+
+     .. code-block:: c
+
+        Py_buffer view;
+        if (PyObject_GetBuffer(obj, &view, PyBUF_SIMPLE) < 0) {
+            return NULL;
+        }
+        // Use `view.buf` and `view.len` to read from the buffer.
+        // You may need to cast buf as `(const char*)view.buf`.
+        PyBuffer_Release(&view);
+
+   * :c:func:`!PyObject_AsWriteBuffer`: Use
+     :c:func:`PyObject_GetBuffer` and :c:func:`PyBuffer_Release` instead:
+
+     .. code-block:: c
+
+        Py_buffer view;
+        if (PyObject_GetBuffer(obj, &view, PyBUF_WRITABLE) < 0) {
+            return NULL;
+        }
+        // Use `view.buf` and `view.len` to write to the buffer.
+        PyBuffer_Release(&view);
+
+  (Contributed by Inada Naoki in :gh:`85275`.)
+
 * Remove the following old functions to configure the Python initialization,
   deprecated in Python 3.11:
 
diff --git a/Grammar/python.gram b/Grammar/python.gram
index 9131835f7421bc..6b2a46aff0dcf0 100644
--- a/Grammar/python.gram
+++ b/Grammar/python.gram
@@ -923,7 +923,7 @@ fstring_conversion[ResultTokenWithMetadata*]:
 fstring_full_format_spec[ResultTokenWithMetadata*]:
     | colon=':' spec=fstring_format_spec* { _PyPegen_setup_full_format_spec(p, colon, (asdl_expr_seq *) spec, EXTRA) }
 fstring_format_spec[expr_ty]:
-    | t=FSTRING_MIDDLE { _PyPegen_constant_from_token(p, t) }
+    | t=FSTRING_MIDDLE { _PyPegen_decoded_constant_from_token(p, t) }
     | fstring_replacement_field
 fstring[expr_ty]:
     | a=FSTRING_START b=fstring_middle* c=FSTRING_END { _PyPegen_joined_str(p, a, (asdl_expr_seq*)b, c) }
diff --git a/Include/Python.h b/Include/Python.h
index 52a7aac6ba6cb6..45ba2ec12f2ad2 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -105,5 +105,6 @@
 #include "fileutils.h"
 #include "cpython/pyfpe.h"
 #include "tracemalloc.h"
+#include "cpython/optimizer.h"
 
 #endif /* !Py_PYTHON_H */
diff --git a/Include/abstract.h b/Include/abstract.h
index b4c2bedef442bf..016ace9bc89e96 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -320,55 +320,6 @@ PyAPI_FUNC(int) PyObject_DelItemString(PyObject *o, const char *key);
 PyAPI_FUNC(int) PyObject_DelItem(PyObject *o, PyObject *key);
 
 
-/* === Old Buffer API ============================================ */
-
-/* FIXME:  usage of these should all be replaced in Python itself
-   but for backwards compatibility we will implement them.
-   Their usage without a corresponding "unlock" mechanism
-   may create issues (but they would already be there). */
-
-/* Takes an arbitrary object which must support the (character, single segment)
-   buffer interface and returns a pointer to a read-only memory location
-   usable as character based input for subsequent processing.
-
-   Return 0 on success.  buffer and buffer_len are only set in case no error
-   occurs. Otherwise, -1 is returned and an exception set. */
-Py_DEPRECATED(3.0)
-PyAPI_FUNC(int) PyObject_AsCharBuffer(PyObject *obj,
-                                      const char **buffer,
-                                      Py_ssize_t *buffer_len);
-
-/* Checks whether an arbitrary object supports the (character, single segment)
-   buffer interface.
-
-   Returns 1 on success, 0 on failure. */
-Py_DEPRECATED(3.0) PyAPI_FUNC(int) PyObject_CheckReadBuffer(PyObject *obj);
-
-/* Same as PyObject_AsCharBuffer() except that this API expects (readable,
-   single segment) buffer interface and returns a pointer to a read-only memory
-   location which can contain arbitrary data.
-
-   0 is returned on success.  buffer and buffer_len are only set in case no
-   error occurs.  Otherwise, -1 is returned and an exception set. */
-Py_DEPRECATED(3.0)
-PyAPI_FUNC(int) PyObject_AsReadBuffer(PyObject *obj,
-                                      const void **buffer,
-                                      Py_ssize_t *buffer_len);
-
-/* Takes an arbitrary object which must support the (writable, single segment)
-   buffer interface and returns a pointer to a writable memory location in
-   buffer of size 'buffer_len'.
-
-   Return 0 on success.  buffer and buffer_len are only set in case no error
-   occurs. Otherwise, -1 is returned and an exception set. */
-Py_DEPRECATED(3.0)
-PyAPI_FUNC(int) PyObject_AsWriteBuffer(PyObject *obj,
-                                       void **buffer,
-                                       Py_ssize_t *buffer_len);
-
-
-/* === New Buffer API ============================================ */
-
 /* Takes an arbitrary object and returns the result of calling
    obj.__format__(format_spec). */
 PyAPI_FUNC(PyObject *) PyObject_Format(PyObject *obj,
diff --git a/Include/cpython/code.h b/Include/cpython/code.h
index 6bead361c79245..1b65b0d01d89f8 100644
--- a/Include/cpython/code.h
+++ b/Include/cpython/code.h
@@ -76,6 +76,13 @@ typedef struct {
     int8_t line_delta;
 } _PyCoLineInstrumentationData;
 
+
+typedef struct {
+    int size;
+    int capacity;
+    struct _PyExecutorObject *executors[1];
+} _PyExecutorArray;
+
 /* Main data structure used for instrumentation.
  * This is allocated when needed for instrumentation
  */
@@ -153,6 +160,7 @@ typedef struct {
     PyObject *co_qualname;        /* unicode (qualname, for reference) */      \
     PyObject *co_linetable;       /* bytes object that holds location info */  \
     PyObject *co_weakreflist;     /* to support weakrefs to code objects */    \
+    _PyExecutorArray *co_executors;      /* executors from optimizer */        \
     _PyCoCached *_co_cached;      /* cached co_* attributes */                 \
     uint64_t _co_instrumentation_version; /* current instrumentation version */  \
     _PyCoMonitoringData *_co_monitoring; /* Monitoring data */                 \
diff --git a/Include/cpython/optimizer.h b/Include/cpython/optimizer.h
new file mode 100644
index 00000000000000..eb257d73f934c6
--- /dev/null
+++ b/Include/cpython/optimizer.h
@@ -0,0 +1,54 @@
+
+#ifndef Py_LIMITED_API
+#ifndef Py_OPTIMIZER_H
+#define Py_OPTIMIZER_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    uint8_t opcode;
+    uint8_t oparg;
+} _PyVMData;
+
+typedef struct _PyExecutorObject {
+    PyObject_HEAD
+    /* WARNING: execute consumes a reference to self. This is necessary to allow executors to tail call into each other. */
+    struct _PyInterpreterFrame *(*execute)(struct _PyExecutorObject *self, struct _PyInterpreterFrame *frame, PyObject **stack_pointer);
+    _PyVMData vm_data; /* Used by the VM, but opaque to the optimizer */
+    /* Data needed by the executor goes here, but is opaque to the VM */
+} _PyExecutorObject;
+
+typedef struct _PyOptimizerObject _PyOptimizerObject;
+
+typedef _PyExecutorObject *(*optimize_func)(_PyOptimizerObject* self, PyCodeObject *code, _Py_CODEUNIT *instr);
+
+typedef struct _PyOptimizerObject {
+    PyObject_HEAD
+    optimize_func optimize;
+    uint16_t resume_threshold;
+    uint16_t backedge_threshold;
+    /* Data needed by the optimizer goes here, but is opaque to the VM */
+} _PyOptimizerObject;
+
+PyAPI_FUNC(int) PyUnstable_Replace_Executor(PyCodeObject *code, _Py_CODEUNIT *instr, _PyExecutorObject *executor);
+
+PyAPI_FUNC(void) PyUnstable_SetOptimizer(_PyOptimizerObject* optimizer);
+
+PyAPI_FUNC(_PyOptimizerObject *) PyUnstable_GetOptimizer(void);
+
+struct _PyInterpreterFrame *
+_PyOptimizer_BackEdge(struct _PyInterpreterFrame *frame, _Py_CODEUNIT *src, _Py_CODEUNIT *dest, PyObject **stack_pointer);
+
+extern _PyOptimizerObject _PyOptimizer_Default;
+
+/* For testing */
+PyAPI_FUNC(PyObject *)PyUnstable_Optimizer_NewCounter(void);
+
+#define OPTIMIZER_BITS_IN_COUNTER 4
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_OPTIMIZER_H */
+#endif /* Py_LIMITED_API */
diff --git a/Include/internal/pycore_code.h b/Include/internal/pycore_code.h
index 75a23f3f5af560..ef940b54b2b086 100644
--- a/Include/internal/pycore_code.h
+++ b/Include/internal/pycore_code.h
@@ -487,6 +487,7 @@ extern int _Py_Instrument(PyCodeObject *co, PyInterpreterState *interp);
 
 extern int _Py_GetBaseOpcode(PyCodeObject *code, int offset);
 
+extern int _PyInstruction_GetLength(PyCodeObject *code, int offset);
 
 #ifdef __cplusplus
 }
diff --git a/Include/internal/pycore_interp.h b/Include/internal/pycore_interp.h
index 04474c1da8855a..a6f4677920ab7e 100644
--- a/Include/internal/pycore_interp.h
+++ b/Include/internal/pycore_interp.h
@@ -160,6 +160,9 @@ struct _is {
     struct types_state types;
     struct callable_cache callable_cache;
     PyCodeObject *interpreter_trampoline;
+    _PyOptimizerObject *optimizer;
+    uint16_t optimizer_resume_threshold;
+    uint16_t optimizer_backedge_threshold;
 
     _Py_Monitors monitors;
     bool f_opcode_trace_set;
diff --git a/Include/internal/pycore_opcode.h b/Include/internal/pycore_opcode.h
index 15d96503830f93..15c8dcfdbe1c70 100644
--- a/Include/internal/pycore_opcode.h
+++ b/Include/internal/pycore_opcode.h
@@ -42,6 +42,7 @@ const uint8_t _PyOpcode_Caches[256] = {
     [LOAD_GLOBAL] = 4,
     [BINARY_OP] = 1,
     [SEND] = 1,
+    [JUMP_BACKWARD] = 1,
     [LOAD_SUPER_ATTR] = 1,
     [CALL] = 3,
 };
@@ -114,6 +115,7 @@ const uint8_t _PyOpcode_Deopt[256] = {
     [END_ASYNC_FOR] = END_ASYNC_FOR,
     [END_FOR] = END_FOR,
     [END_SEND] = END_SEND,
+    [ENTER_EXECUTOR] = ENTER_EXECUTOR,
     [EXTENDED_ARG] = EXTENDED_ARG,
     [FORMAT_VALUE] = FORMAT_VALUE,
     [FOR_ITER] = FOR_ITER,
@@ -475,7 +477,7 @@ static const char *const _PyOpcode_OpName[267] = {
     [227] = "<227>",
     [228] = "<228>",
     [229] = "<229>",
-    [230] = "<230>",
+    [ENTER_EXECUTOR] = "ENTER_EXECUTOR",
     [231] = "<231>",
     [232] = "<232>",
     [233] = "<233>",
@@ -571,7 +573,6 @@ static const char *const _PyOpcode_OpName[267] = {
     case 227: \
     case 228: \
     case 229: \
-    case 230: \
     case 231: \
     case 232: \
     case 233: \
diff --git a/Include/opcode.h b/Include/opcode.h
index 9806511ba4286a..bbf5756a352108 100644
--- a/Include/opcode.h
+++ b/Include/opcode.h
@@ -120,6 +120,7 @@ extern "C" {
 #define CALL_INTRINSIC_2                       174
 #define LOAD_FROM_DICT_OR_GLOBALS              175
 #define LOAD_FROM_DICT_OR_DEREF                176
+#define ENTER_EXECUTOR                         230
 #define MIN_INSTRUMENTED_OPCODE                237
 #define INSTRUMENTED_LOAD_SUPER_ATTR           237
 #define INSTRUMENTED_POP_JUMP_IF_NONE          238
diff --git a/Include/pystats.h b/Include/pystats.h
index 4b961bad2a43e4..034bf05bfe290f 100644
--- a/Include/pystats.h
+++ b/Include/pystats.h
@@ -70,6 +70,7 @@ typedef struct _object_stats {
     uint64_t type_cache_dunder_hits;
     uint64_t type_cache_dunder_misses;
     uint64_t type_cache_collisions;
+    uint64_t optimization_attempts;
 } ObjectStats;
 
 typedef struct _stats {
diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py
index 73ac4405cb54cf..cca0f82be49523 100644
--- a/Lib/importlib/_bootstrap_external.py
+++ b/Lib/importlib/_bootstrap_external.py
@@ -445,8 +445,9 @@ def _write_atomic(path, data, mode=0o666):
 #     Python 3.12b1 3529 (Inline list/dict/set comprehensions)
 #     Python 3.12b1 3530 (Shrink the LOAD_SUPER_ATTR caches)
 #     Python 3.12b1 3531 (Add PEP 695 changes)
+#     Python 3.13a1 3550 (Plugin optimizer support)
 
-#     Python 3.13 will start with 3550
+#     Python 3.14 will start with 3600
 
 #     Please don't copy-paste the same pre-release tag for new entries above!!!
 #     You should always use the *upcoming* tag. For example, if 3.12a6 came out
@@ -461,7 +462,7 @@ 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 = (3531).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3550).to_bytes(2, 'little') + b'\r\n'
 
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 
diff --git a/Lib/opcode.py b/Lib/opcode.py
index 6bb2f1c140b15a..b33302949f2490 100644
--- a/Lib/opcode.py
+++ b/Lib/opcode.py
@@ -232,6 +232,9 @@ def pseudo_op(name, op, real_ops):
 def_op('LOAD_FROM_DICT_OR_DEREF', 176)
 hasfree.append(176)
 
+# Optimizer hook
+def_op('ENTER_EXECUTOR', 230)
+
 # Instrumented instructions
 MIN_INSTRUMENTED_OPCODE = 237
 
@@ -486,6 +489,9 @@ def pseudo_op(name, op, real_ops):
     "SEND": {
         "counter": 1,
     },
+    "JUMP_BACKWARD": {
+        "counter": 1,
+    },
 }
 
 _inline_cache_entries = [
diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index 76edbf5121c806..ffd082ec11806a 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -1591,6 +1591,8 @@ def test_funcdef(self):
         f = ast.FunctionDef("x", a, [ast.Pass()], [],
                             ast.Name("x", ast.Store()), None, [])
         self.stmt(f, "must have Load context")
+        f = ast.FunctionDef("x", ast.arguments(), [ast.Pass()])
+        self.stmt(f)
         def fac(args):
             return ast.FunctionDef("x", args, [ast.Pass()], [], None, None, [])
         self._check_arguments(fac, self.stmt)
diff --git a/Lib/test/test_capi/test_misc.py b/Lib/test/test_capi/test_misc.py
index e1b55cffe8ff52..3a4937c3bf5faf 100644
--- a/Lib/test/test_capi/test_misc.py
+++ b/Lib/test/test_capi/test_misc.py
@@ -1916,6 +1916,19 @@ def func():
         names = ["func", "outer", "outer", "inner", "inner", "outer", "inner"]
         self.do_test(func, names)
 
+class TestOptimizerAPI(unittest.TestCase):
+
+    def test_counter_optimizer(self):
+        opt = _testinternalcapi.get_counter_optimizer()
+        self.assertEqual(opt.get_count(), 0)
+        try:
+            _testinternalcapi.set_optimizer(opt)
+            self.assertEqual(opt.get_count(), 0)
+            for _ in range(1000):
+                pass
+            self.assertEqual(opt.get_count(), 1000)
+        finally:
+            _testinternalcapi.set_optimizer(None)
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
index c90702a408eb33..affba12985548f 100644
--- a/Lib/test/test_dis.py
+++ b/Lib/test/test_dis.py
@@ -138,10 +138,10 @@ def bug708901():
 
 %3d        CALL                     2
            GET_ITER
-        >> FOR_ITER                 2 (to 34)
+        >> FOR_ITER                 3 (to 36)
            STORE_FAST               0 (res)
 
-%3d        JUMP_BACKWARD            4 (to 26)
+%3d        JUMP_BACKWARD            5 (to 26)
 
 %3d     >> END_FOR
            RETURN_CONST             0 (None)
@@ -384,7 +384,7 @@ def wrap_func_w_kwargs():
            BINARY_OP               13 (+=)
            STORE_NAME               0 (x)
 
-  2        JUMP_BACKWARD            6 (to 8)
+  2        JUMP_BACKWARD            7 (to 8)
 """
 
 dis_traceback = """\
@@ -552,20 +552,20 @@ async def _asyncwith(c):
            RETURN_CONST             0 (None)
 
 %3d     >> CLEANUP_THROW
-           JUMP_BACKWARD           25 (to 24)
+           JUMP_BACKWARD           26 (to 24)
         >> CLEANUP_THROW
-           JUMP_BACKWARD            9 (to 60)
+           JUMP_BACKWARD           11 (to 60)
         >> PUSH_EXC_INFO
            WITH_EXCEPT_START
            GET_AWAITABLE            2
            LOAD_CONST               0 (None)
-        >> SEND                     4 (to 98)
+        >> SEND                     4 (to 102)
            YIELD_VALUE              3
            RESUME                   3
-           JUMP_BACKWARD_NO_INTERRUPT     5 (to 86)
+           JUMP_BACKWARD_NO_INTERRUPT     5 (to 90)
         >> CLEANUP_THROW
         >> END_SEND
-           POP_JUMP_IF_TRUE         1 (to 104)
+           POP_JUMP_IF_TRUE         1 (to 108)
            RERAISE                  2
         >> POP_TOP
            POP_EXCEPT
@@ -732,7 +732,7 @@ def foo(x):
            POP_TOP
            RESUME                   0
            LOAD_FAST                0 (.0)
-        >> FOR_ITER                 9 (to 32)
+        >> FOR_ITER                10 (to 34)
            STORE_FAST               1 (z)
            LOAD_DEREF               2 (x)
            LOAD_FAST                1 (z)
@@ -740,7 +740,7 @@ def foo(x):
            YIELD_VALUE              1
            RESUME                   1
            POP_TOP
-           JUMP_BACKWARD           11 (to 10)
+           JUMP_BACKWARD           12 (to 10)
         >> END_FOR
            RETURN_CONST             0 (None)
         >> CALL_INTRINSIC_1         3 (INTRINSIC_STOPITERATION_ERROR)
@@ -786,14 +786,14 @@ def loop_test():
            LOAD_CONST               2 (3)
            BINARY_OP                5 (*)
            GET_ITER
-        >> FOR_ITER_LIST           13 (to 46)
+        >> FOR_ITER_LIST           14 (to 48)
            STORE_FAST               0 (i)
 
 %3d        LOAD_GLOBAL_MODULE       1 (NULL + load_test)
            LOAD_FAST                0 (i)
            CALL_PY_WITH_DEFAULTS     1
            POP_TOP
-           JUMP_BACKWARD           15 (to 16)
+           JUMP_BACKWARD           16 (to 16)
 
 %3d     >> END_FOR
            RETURN_CONST             0 (None)
@@ -1277,7 +1277,7 @@ def test_show_caches(self):
                     caches = list(self.get_cached_values(quickened, adaptive))
                     for cache in caches:
                         self.assertRegex(cache, pattern)
-                    total_caches = 20
+                    total_caches = 21
                     empty_caches = 7
                     self.assertEqual(caches.count(""), empty_caches)
                     self.assertEqual(len(caches), total_caches)
@@ -1653,13 +1653,14 @@ def _prepare_test_cases():
   Instruction(opname='RETURN_CONST', opcode=121, arg=0, argval=None, argrepr='None', offset=36, starts_line=None, is_jump_target=False, positions=None),
 ]
 
+
 expected_opinfo_jumpy = [
   Instruction(opname='RESUME', opcode=151, arg=0, argval=0, argrepr='', offset=0, starts_line=1, is_jump_target=False, positions=None),
   Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='range', argrepr='NULL + range', offset=2, starts_line=3, is_jump_target=False, positions=None),
   Instruction(opname='LOAD_CONST', opcode=100, arg=1, argval=10, argrepr='10', offset=12, starts_line=None, is_jump_target=False, positions=None),
   Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=14, starts_line=None, is_jump_target=False, positions=None),
   Instruction(opname='GET_ITER', opcode=68, arg=None, argval=None, argrepr='', offset=22, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='FOR_ITER', opcode=93, arg=26, argval=80, argrepr='to 80', offset=24, starts_line=None, is_jump_target=True, positions=None),
+  Instruction(opname='FOR_ITER', opcode=93, arg=28, argval=84, argrepr='to 84', offset=24, starts_line=None, is_jump_target=True, positions=None),
   Instruction(opname='STORE_FAST', opcode=125, arg=0, argval='i', argrepr='i', offset=28, starts_line=None, is_jump_target=False, positions=None),
   Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=30, starts_line=4, is_jump_target=False, positions=None),
   Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=40, starts_line=None, is_jump_target=False, positions=None),
@@ -1668,105 +1669,105 @@ def _prepare_test_cases():
   Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=52, starts_line=5, is_jump_target=False, positions=None),
   Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=54, starts_line=None, is_jump_target=False, positions=None),
   Instruction(opname='COMPARE_OP', opcode=107, arg=2, argval='<', argrepr='<', offset=56, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=1, argval=64, argrepr='to 64', offset=60, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=20, argval=24, argrepr='to 24', offset=62, starts_line=6, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=64, starts_line=7, is_jump_target=True, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=66, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='COMPARE_OP', opcode=107, arg=68, argval='>', argrepr='>', offset=68, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=1, argval=76, argrepr='to 76', offset=72, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=26, argval=24, argrepr='to 24', offset=74, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=76, starts_line=8, is_jump_target=True, positions=None),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=12, argval=104, argrepr='to 104', offset=78, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='END_FOR', opcode=4, arg=None, argval=None, argrepr='', offset=80, starts_line=3, is_jump_target=True, positions=None),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=82, starts_line=10, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=4, argval='I can haz else clause?', argrepr="'I can haz else clause?'", offset=92, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=94, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=102, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_FAST_CHECK', opcode=127, arg=0, argval='i', argrepr='i', offset=104, starts_line=11, is_jump_target=True, positions=None),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=31, argval=170, argrepr='to 170', offset=106, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=108, starts_line=12, is_jump_target=True, positions=None),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=118, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=120, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=128, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=130, starts_line=13, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=132, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='BINARY_OP', opcode=122, arg=23, argval=23, argrepr='-=', offset=134, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='STORE_FAST', opcode=125, arg=0, argval='i', argrepr='i', offset=138, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=140, starts_line=14, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=142, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='COMPARE_OP', opcode=107, arg=68, argval='>', argrepr='>', offset=144, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=1, argval=152, argrepr='to 152', offset=148, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=24, argval=104, argrepr='to 104', offset=150, starts_line=15, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=152, starts_line=16, is_jump_target=True, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=154, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='COMPARE_OP', opcode=107, arg=2, argval='<', argrepr='<', offset=156, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=1, argval=164, argrepr='to 164', offset=160, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=14, argval=192, argrepr='to 192', offset=162, starts_line=17, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=164, starts_line=11, is_jump_target=True, positions=None),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=2, argval=66, argrepr='to 66', offset=60, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=21, argval=24, argrepr='to 24', offset=62, starts_line=6, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=66, starts_line=7, is_jump_target=True, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=68, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='COMPARE_OP', opcode=107, arg=68, argval='>', argrepr='>', offset=70, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=2, argval=80, argrepr='to 80', offset=74, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=28, argval=24, argrepr='to 24', offset=76, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=80, starts_line=8, is_jump_target=True, positions=None),
+  Instruction(opname='JUMP_FORWARD', opcode=110, arg=12, argval=108, argrepr='to 108', offset=82, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='END_FOR', opcode=4, arg=None, argval=None, argrepr='', offset=84, starts_line=3, is_jump_target=True, positions=None),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=86, starts_line=10, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=4, argval='I can haz else clause?', argrepr="'I can haz else clause?'", offset=96, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=98, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=106, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_FAST_CHECK', opcode=127, arg=0, argval='i', argrepr='i', offset=108, starts_line=11, is_jump_target=True, positions=None),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=33, argval=178, argrepr='to 178', offset=110, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=112, starts_line=12, is_jump_target=True, positions=None),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=122, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=124, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=132, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=134, starts_line=13, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=136, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='BINARY_OP', opcode=122, arg=23, argval=23, argrepr='-=', offset=138, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='STORE_FAST', opcode=125, arg=0, argval='i', argrepr='i', offset=142, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=144, starts_line=14, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=146, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='COMPARE_OP', opcode=107, arg=68, argval='>', argrepr='>', offset=148, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=2, argval=158, argrepr='to 158', offset=152, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=25, argval=108, argrepr='to 108', offset=154, starts_line=15, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=158, starts_line=16, is_jump_target=True, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=160, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='COMPARE_OP', opcode=107, arg=2, argval='<', argrepr='<', offset=162, starts_line=None, is_jump_target=False, positions=None),
   Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=1, argval=170, argrepr='to 170', offset=166, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=31, argval=108, argrepr='to 108', offset=168, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=170, starts_line=19, is_jump_target=True, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=6, argval='Who let lolcatz into this test suite?', argrepr="'Who let lolcatz into this test suite?'", offset=180, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=182, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=190, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='NOP', opcode=9, arg=None, argval=None, argrepr='', offset=192, starts_line=20, is_jump_target=True, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=194, starts_line=21, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=7, argval=0, argrepr='0', offset=196, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='BINARY_OP', opcode=122, arg=11, argval=11, argrepr='/', offset=198, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=202, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=204, starts_line=25, is_jump_target=False, positions=None),
-  Instruction(opname='BEFORE_WITH', opcode=53, arg=None, argval=None, argrepr='', offset=206, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='STORE_FAST', opcode=125, arg=1, argval='dodgy', argrepr='dodgy', offset=208, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=210, starts_line=26, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=8, argval='Never reach this', argrepr="'Never reach this'", offset=220, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=222, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=230, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=232, starts_line=25, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=234, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=236, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='CALL', opcode=171, arg=2, argval=2, argrepr='', offset=238, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=246, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=248, starts_line=28, is_jump_target=True, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=258, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=260, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=268, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='RETURN_CONST', opcode=121, arg=0, argval=None, argrepr='None', offset=270, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='PUSH_EXC_INFO', opcode=35, arg=None, argval=None, argrepr='', offset=272, starts_line=25, is_jump_target=False, positions=None),
-  Instruction(opname='WITH_EXCEPT_START', opcode=49, arg=None, argval=None, argrepr='', offset=274, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=1, argval=280, argrepr='to 280', offset=276, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='RERAISE', opcode=119, arg=2, argval=2, argrepr='', offset=278, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=280, starts_line=None, is_jump_target=True, positions=None),
-  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=282, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=284, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=286, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=21, argval=248, argrepr='to 248', offset=288, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='COPY', opcode=120, arg=3, argval=3, argrepr='', offset=290, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=292, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='RERAISE', opcode=119, arg=1, argval=1, argrepr='', offset=294, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='PUSH_EXC_INFO', opcode=35, arg=None, argval=None, argrepr='', offset=296, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=4, argval='ZeroDivisionError', argrepr='ZeroDivisionError', offset=298, starts_line=22, is_jump_target=False, positions=None),
-  Instruction(opname='CHECK_EXC_MATCH', opcode=36, arg=None, argval=None, argrepr='', offset=308, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=14, argval=340, argrepr='to 340', offset=310, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=312, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=314, starts_line=23, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=9, argval='Here we go, here we go, here we go...', argrepr="'Here we go, here we go, here we go...'", offset=324, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=326, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=334, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=336, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=46, argval=248, argrepr='to 248', offset=338, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='RERAISE', opcode=119, arg=0, argval=0, argrepr='', offset=340, starts_line=22, is_jump_target=True, positions=None),
-  Instruction(opname='COPY', opcode=120, arg=3, argval=3, argrepr='', offset=342, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=344, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='RERAISE', opcode=119, arg=1, argval=1, argrepr='', offset=346, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='PUSH_EXC_INFO', opcode=35, arg=None, argval=None, argrepr='', offset=348, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=350, starts_line=28, is_jump_target=False, positions=None),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=360, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=362, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=370, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='RERAISE', opcode=119, arg=0, argval=0, argrepr='', offset=372, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='COPY', opcode=120, arg=3, argval=3, argrepr='', offset=374, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=376, starts_line=None, is_jump_target=False, positions=None),
-  Instruction(opname='RERAISE', opcode=119, arg=1, argval=1, argrepr='', offset=378, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='JUMP_FORWARD', opcode=110, arg=15, argval=200, argrepr='to 200', offset=168, starts_line=17, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=170, starts_line=11, is_jump_target=True, positions=None),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=2, argval=178, argrepr='to 178', offset=172, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=33, argval=112, argrepr='to 112', offset=174, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=178, starts_line=19, is_jump_target=True, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=6, argval='Who let lolcatz into this test suite?', argrepr="'Who let lolcatz into this test suite?'", offset=188, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=190, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=198, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='NOP', opcode=9, arg=None, argval=None, argrepr='', offset=200, starts_line=20, is_jump_target=True, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=202, starts_line=21, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=7, argval=0, argrepr='0', offset=204, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='BINARY_OP', opcode=122, arg=11, argval=11, argrepr='/', offset=206, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=210, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=212, starts_line=25, is_jump_target=False, positions=None),
+  Instruction(opname='BEFORE_WITH', opcode=53, arg=None, argval=None, argrepr='', offset=214, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='STORE_FAST', opcode=125, arg=1, argval='dodgy', argrepr='dodgy', offset=216, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=218, starts_line=26, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=8, argval='Never reach this', argrepr="'Never reach this'", offset=228, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=230, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=238, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=240, starts_line=25, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=242, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=244, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='CALL', opcode=171, arg=2, argval=2, argrepr='', offset=246, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=254, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=256, starts_line=28, is_jump_target=True, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=266, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=268, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=276, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='RETURN_CONST', opcode=121, arg=0, argval=None, argrepr='None', offset=278, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='PUSH_EXC_INFO', opcode=35, arg=None, argval=None, argrepr='', offset=280, starts_line=25, is_jump_target=False, positions=None),
+  Instruction(opname='WITH_EXCEPT_START', opcode=49, arg=None, argval=None, argrepr='', offset=282, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=1, argval=288, argrepr='to 288', offset=284, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='RERAISE', opcode=119, arg=2, argval=2, argrepr='', offset=286, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=288, starts_line=None, is_jump_target=True, positions=None),
+  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=290, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=292, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=294, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=22, argval=256, argrepr='to 256', offset=296, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='COPY', opcode=120, arg=3, argval=3, argrepr='', offset=300, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=302, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='RERAISE', opcode=119, arg=1, argval=1, argrepr='', offset=304, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='PUSH_EXC_INFO', opcode=35, arg=None, argval=None, argrepr='', offset=306, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=4, argval='ZeroDivisionError', argrepr='ZeroDivisionError', offset=308, starts_line=22, is_jump_target=False, positions=None),
+  Instruction(opname='CHECK_EXC_MATCH', opcode=36, arg=None, argval=None, argrepr='', offset=318, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=15, argval=352, argrepr='to 352', offset=320, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=322, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=324, starts_line=23, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=9, argval='Here we go, here we go, here we go...', argrepr="'Here we go, here we go, here we go...'", offset=334, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=336, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=344, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=346, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='JUMP_BACKWARD', opcode=140, arg=48, argval=256, argrepr='to 256', offset=348, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='RERAISE', opcode=119, arg=0, argval=0, argrepr='', offset=352, starts_line=22, is_jump_target=True, positions=None),
+  Instruction(opname='COPY', opcode=120, arg=3, argval=3, argrepr='', offset=354, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=356, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='RERAISE', opcode=119, arg=1, argval=1, argrepr='', offset=358, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='PUSH_EXC_INFO', opcode=35, arg=None, argval=None, argrepr='', offset=360, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=3, argval='print', argrepr='NULL + print', offset=362, starts_line=28, is_jump_target=False, positions=None),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=372, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='CALL', opcode=171, arg=1, argval=1, argrepr='', offset=374, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=382, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='RERAISE', opcode=119, arg=0, argval=0, argrepr='', offset=384, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='COPY', opcode=120, arg=3, argval=3, argrepr='', offset=386, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=388, starts_line=None, is_jump_target=False, positions=None),
+  Instruction(opname='RERAISE', opcode=119, arg=1, argval=1, argrepr='', offset=390, starts_line=None, is_jump_target=False, positions=None),
 ]
 
 # One last piece of inspect fodder to check the default line number handling
diff --git a/Lib/test/test_fstring.py b/Lib/test/test_fstring.py
index 3ba2f943e6e968..031b94d8d58a39 100644
--- a/Lib/test/test_fstring.py
+++ b/Lib/test/test_fstring.py
@@ -764,6 +764,16 @@ def test_format_specifier_expressions(self):
                              """f'{"s"!{"r"}}'""",
                              ])
 
+    def test_custom_format_specifier(self):
+        class CustomFormat:
+            def __format__(self, format_spec):
+                return format_spec
+
+        self.assertEqual(f'{CustomFormat():\n}', '\n')
+        self.assertEqual(f'{CustomFormat():\u2603}', '☃')
+        with self.assertWarns(SyntaxWarning):
+            exec('f"{F():¯\_(ツ)_/¯}"', {'F': CustomFormat})
+
     def test_side_effect_order(self):
         class X:
             def __init__(self):
diff --git a/Lib/test/test_monitoring.py b/Lib/test/test_monitoring.py
index 46b817d74f092f..ef4a79aefd646b 100644
--- a/Lib/test/test_monitoring.py
+++ b/Lib/test/test_monitoring.py
@@ -1425,3 +1425,38 @@ def f():
 
     def test_get_local_events_uninitialized(self):
         self.assertEqual(sys.monitoring.get_local_events(TEST_TOOL, self.f.__code__), 0)
+
+class TestRegressions(MonitoringTestBase, unittest.TestCase):
+
+    def test_105162(self):
+        caught = None
+
+        def inner():
+            nonlocal caught
+            try:
+                yield
+            except Exception:
+                caught = "inner"
+                yield
+
+        def outer():
+            nonlocal caught
+            try:
+                yield from inner()
+            except Exception:
+                caught = "outer"
+                yield
+
+        def run():
+            gen = outer()
+            gen.send(None)
+            gen.throw(Exception)
+        run()
+        self.assertEqual(caught, "inner")
+        caught = None
+        try:
+            sys.monitoring.set_events(TEST_TOOL, E.PY_RESUME)
+            run()
+            self.assertEqual(caught, "inner")
+        finally:
+            sys.monitoring.set_events(TEST_TOOL, 0)
diff --git a/Makefile.pre.in b/Makefile.pre.in
index 0ab46a2a70ec3a..b66530928eeea9 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -403,6 +403,7 @@ PYTHON_OBJS=	\
 		Python/modsupport.o \
 		Python/mysnprintf.o \
 		Python/mystrtoul.o \
+		Python/optimizer.o \
 		Python/pathconfig.o \
 		Python/preconfig.o \
 		Python/pyarena.o \
diff --git a/Misc/NEWS.d/next/C API/2023-05-25-15-44-48.gh-issue-104584.cSAoRh.rst b/Misc/NEWS.d/next/C API/2023-05-25-15-44-48.gh-issue-104584.cSAoRh.rst
new file mode 100644
index 00000000000000..9ce0373e8ac9d4
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2023-05-25-15-44-48.gh-issue-104584.cSAoRh.rst	
@@ -0,0 +1,2 @@
+Add an unstable C API for hooking in an optimizer. This is mainly internal,
+but marked "unstable" to allow third-party experimentation.
diff --git a/Misc/NEWS.d/next/C API/2023-05-31-19-38-45.gh-issue-85275.doojgE.rst b/Misc/NEWS.d/next/C API/2023-05-31-19-38-45.gh-issue-85275.doojgE.rst
new file mode 100644
index 00000000000000..082b77b9035cbe
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2023-05-31-19-38-45.gh-issue-85275.doojgE.rst	
@@ -0,0 +1,4 @@
+``PyObject_AsCharBuffer()``, ``PyObject_AsReadBuffer()``,
+``PyObject_CheckReadBuffer()``, and ``PyObject_AsWriteBuffer()`` are
+removed. Please migrate to new buffer protocol; :c:func:`PyObject_GetBuffer`
+and :c:func:`PyBuffer_Release`.
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-05-31-08-10-59.gh-issue-104799.8kDWti.rst b/Misc/NEWS.d/next/Core and Builtins/2023-05-31-08-10-59.gh-issue-104799.8kDWti.rst
new file mode 100644
index 00000000000000..e1fe47f862529c
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2023-05-31-08-10-59.gh-issue-104799.8kDWti.rst	
@@ -0,0 +1,4 @@
+Attributes of :mod:`ast` nodes that are lists now default to the empty list
+if omitted. This means that some code that previously raised
+:exc:`TypeError` when the AST node was used will now proceed with the empty
+list instead. Patch by Jelle Zijlstra.
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-06-01-11-37-03.gh-issue-105162.r8VCXk.rst b/Misc/NEWS.d/next/Core and Builtins/2023-06-01-11-37-03.gh-issue-105162.r8VCXk.rst
new file mode 100644
index 00000000000000..adb4e8478d9c55
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2023-06-01-11-37-03.gh-issue-105162.r8VCXk.rst	
@@ -0,0 +1,2 @@
+Fixed bug in generator.close()/throw() where an inner iterator would be
+ignored when the outer iterator was instrumented.
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-06-02-11-37-12.gh-issue-105194.4eu56B.rst b/Misc/NEWS.d/next/Core and Builtins/2023-06-02-11-37-12.gh-issue-105194.4eu56B.rst
new file mode 100644
index 00000000000000..adee74f5894b54
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2023-06-02-11-37-12.gh-issue-105194.4eu56B.rst	
@@ -0,0 +1,2 @@
+Do not escape with backslashes f-string format specifiers. Patch by Pablo
+Galindo
diff --git a/Misc/stable_abi.toml b/Misc/stable_abi.toml
index 2209f6e02cfcd1..4d833878734d08 100644
--- a/Misc/stable_abi.toml
+++ b/Misc/stable_abi.toml
@@ -1755,12 +1755,16 @@
 
 [function.PyObject_AsCharBuffer]
     added = '3.2'
+    abi_only = true
 [function.PyObject_AsReadBuffer]
     added = '3.2'
+    abi_only = true
 [function.PyObject_AsWriteBuffer]
     added = '3.2'
+    abi_only = true
 [function.PyObject_CheckReadBuffer]
     added = '3.2'
+    abi_only = true
 
 # Flags are implicitly part of the ABI:
 
diff --git a/Modules/_testinternalcapi.c b/Modules/_testinternalcapi.c
index 8267dbf6779017..b43dc7fbf3236c 100644
--- a/Modules/_testinternalcapi.c
+++ b/Modules/_testinternalcapi.c
@@ -822,6 +822,22 @@ iframe_getlasti(PyObject *self, PyObject *frame)
     return PyLong_FromLong(PyUnstable_InterpreterFrame_GetLasti(f));
 }
 
+static PyObject *
+get_counter_optimizer(PyObject *self, PyObject *arg)
+{
+    return PyUnstable_Optimizer_NewCounter();
+}
+
+static PyObject *
+set_optimizer(PyObject *self, PyObject *opt)
+{
+    if (opt == Py_None) {
+        opt = NULL;
+    }
+    PyUnstable_SetOptimizer((_PyOptimizerObject*)opt);
+    Py_RETURN_NONE;
+}
+
 static PyMethodDef module_functions[] = {
     {"get_configs", get_configs, METH_NOARGS},
     {"get_recursion_depth", get_recursion_depth, METH_NOARGS},
@@ -850,6 +866,8 @@ static PyMethodDef module_functions[] = {
     {"iframe_getcode", iframe_getcode, METH_O, NULL},
     {"iframe_getline", iframe_getline, METH_O, NULL},
     {"iframe_getlasti", iframe_getlasti, METH_O, NULL},
+    {"set_optimizer", set_optimizer,  METH_O, NULL},
+    {"get_counter_optimizer", get_counter_optimizer, METH_NOARGS, NULL},
     {NULL, NULL} /* sentinel */
 };
 
diff --git a/Objects/abstract.c b/Objects/abstract.c
index e95785900c9c5f..00087bd86624ee 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -294,11 +294,17 @@ PyObject_CheckBuffer(PyObject *obj)
     return (tp_as_buffer != NULL && tp_as_buffer->bf_getbuffer != NULL);
 }
 
+// Old buffer protocols (deprecated, abi only)
 
-/* We release the buffer right after use of this function which could
+/* Checks whether an arbitrary object supports the (character, single segment)
+   buffer interface.
+
+   Returns 1 on success, 0 on failure.
+
+   We release the buffer right after use of this function which could
    cause issues later on.  Don't use these functions in new code.
  */
-int
+PyAPI_FUNC(int) /* abi_only */
 PyObject_CheckReadBuffer(PyObject *obj)
 {
     PyBufferProcs *pb = Py_TYPE(obj)->tp_as_buffer;
@@ -333,7 +339,13 @@ as_read_buffer(PyObject *obj, const void **buffer, Py_ssize_t *buffer_len)
     return 0;
 }
 
-int
+/* Takes an arbitrary object which must support the (character, single segment)
+   buffer interface and returns a pointer to a read-only memory location
+   usable as character based input for subsequent processing.
+
+   Return 0 on success.  buffer and buffer_len are only set in case no error
+   occurs. Otherwise, -1 is returned and an exception set. */
+PyAPI_FUNC(int) /* abi_only */
 PyObject_AsCharBuffer(PyObject *obj,
                       const char **buffer,
                       Py_ssize_t *buffer_len)
@@ -341,16 +353,30 @@ PyObject_AsCharBuffer(PyObject *obj,
     return as_read_buffer(obj, (const void **)buffer, buffer_len);
 }
 
-int PyObject_AsReadBuffer(PyObject *obj,
-                          const void **buffer,
-                          Py_ssize_t *buffer_len)
+/* Same as PyObject_AsCharBuffer() except that this API expects (readable,
+   single segment) buffer interface and returns a pointer to a read-only memory
+   location which can contain arbitrary data.
+
+   0 is returned on success.  buffer and buffer_len are only set in case no
+   error occurs.  Otherwise, -1 is returned and an exception set. */
+PyAPI_FUNC(int) /* abi_only */
+PyObject_AsReadBuffer(PyObject *obj,
+                      const void **buffer,
+                      Py_ssize_t *buffer_len)
 {
     return as_read_buffer(obj, buffer, buffer_len);
 }
 
-int PyObject_AsWriteBuffer(PyObject *obj,
-                           void **buffer,
-                           Py_ssize_t *buffer_len)
+/* Takes an arbitrary object which must support the (writable, single segment)
+   buffer interface and returns a pointer to a writable memory location in
+   buffer of size 'buffer_len'.
+
+   Return 0 on success.  buffer and buffer_len are only set in case no error
+   occurs. Otherwise, -1 is returned and an exception set. */
+PyAPI_FUNC(int) /* abi_only */
+PyObject_AsWriteBuffer(PyObject *obj,
+                       void **buffer,
+                       Py_ssize_t *buffer_len)
 {
     PyBufferProcs *pb;
     Py_buffer view;
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index ebae0a3ec5951b..cf087e8d3fbeb9 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -433,6 +433,7 @@ init_code(PyCodeObject *co, struct _PyCodeConstructor *con)
     co->co_weakreflist = NULL;
     co->co_extra = NULL;
     co->_co_cached = NULL;
+    co->co_executors = NULL;
 
     memcpy(_PyCode_CODE(co), PyBytes_AS_STRING(con->code),
            PyBytes_GET_SIZE(con->code));
@@ -1677,6 +1678,12 @@ code_dealloc(PyCodeObject *co)
 
         PyMem_Free(co_extra);
     }
+    if (co->co_executors != NULL) {
+        for (int i = 0; i < co->co_executors->size; i++) {
+            Py_CLEAR(co->co_executors->executors[i]);
+        }
+        PyMem_Free(co->co_executors);
+    }
 
     Py_XDECREF(co->co_consts);
     Py_XDECREF(co->co_names);
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 2c90a6b71311ca..f2061e6a18fa40 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -348,7 +348,7 @@ mark_stacks(PyCodeObject *code_obj, int len)
                     break;
                 case JUMP_BACKWARD:
                 case JUMP_BACKWARD_NO_INTERRUPT:
-                    j = i + 1 - oparg;
+                    j = next_i - oparg;
                     assert(j >= 0);
                     assert(j < len);
                     if (stacks[j] == UNINITIALIZED && j < i) {
diff --git a/Objects/genobject.c b/Objects/genobject.c
index 7a295dc239d632..5c93ef49583b1e 100644
--- a/Objects/genobject.c
+++ b/Objects/genobject.c
@@ -331,6 +331,18 @@ gen_close_iter(PyObject *yf)
     return 0;
 }
 
+static inline bool
+is_resume(_Py_CODEUNIT *instr)
+{
+    return instr->op.code == RESUME || instr->op.code == INSTRUMENTED_RESUME;
+}
+
+static inline bool
+is_yield(_Py_CODEUNIT *instr)
+{
+    return instr->op.code == YIELD_VALUE || instr->op.code == INSTRUMENTED_YIELD_VALUE;
+}
+
 PyObject *
 _PyGen_yf(PyGenObject *gen)
 {
@@ -347,7 +359,7 @@ _PyGen_yf(PyGenObject *gen)
             return NULL;
         }
         _Py_CODEUNIT next = frame->prev_instr[1];
-        if (next.op.code != RESUME || next.op.arg < 2)
+        if (!is_resume(&next) || next.op.arg < 2)
         {
             /* Not in a yield from */
             return NULL;
@@ -382,8 +394,8 @@ gen_close(PyGenObject *gen, PyObject *args)
     _PyInterpreterFrame *frame = (_PyInterpreterFrame *)gen->gi_iframe;
     /* It is possible for the previous instruction to not be a
      * YIELD_VALUE if the debugger has changed the lineno. */
-    if (err == 0 && frame->prev_instr[0].op.code == YIELD_VALUE) {
-        assert(frame->prev_instr[1].op.code == RESUME);
+    if (err == 0 && is_yield(frame->prev_instr)) {
+        assert(is_resume(frame->prev_instr + 1));
         int exception_handler_depth = frame->prev_instr[0].op.code;
         assert(exception_handler_depth > 0);
         /* We can safely ignore the outermost try block
diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
index 3df0a072045208..87f08e857d0e29 100644
--- a/PCbuild/_freeze_module.vcxproj
+++ b/PCbuild/_freeze_module.vcxproj
@@ -216,6 +216,7 @@
     <ClCompile Include="..\Python\modsupport.c" />
     <ClCompile Include="..\Python\mysnprintf.c" />
     <ClCompile Include="..\Python\mystrtoul.c" />
+    <ClCompile Include="..\Python\optimizer.c" />
     <ClCompile Include="..\Python\pathconfig.c" />
     <ClCompile Include="..\Python\perf_trampoline.c" />
     <ClCompile Include="..\Python\preconfig.c" />
diff --git a/PCbuild/_freeze_module.vcxproj.filters b/PCbuild/_freeze_module.vcxproj.filters
index d98a4c5ae4e2bb..3dae8cca7a2d56 100644
--- a/PCbuild/_freeze_module.vcxproj.filters
+++ b/PCbuild/_freeze_module.vcxproj.filters
@@ -277,6 +277,9 @@
     <ClCompile Include="..\Objects\odictobject.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\Python\optimizer.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\Parser\parser.c">
       <Filter>Source Files</Filter>
     </ClCompile>
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index d899332a9e6ed5..611dba3dbb7f12 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -540,6 +540,7 @@
     <ClCompile Include="..\Python\modsupport.c" />
     <ClCompile Include="..\Python\mysnprintf.c" />
     <ClCompile Include="..\Python\mystrtoul.c" />
+    <ClCompile Include="..\Python\optimizer.c" />
     <ClCompile Include="..\Python\pathconfig.c" />
     <ClCompile Include="..\Python\perf_trampoline.c" />
     <ClCompile Include="..\Python\preconfig.c" />
diff --git a/PCbuild/pythoncore.vcxproj.filters b/PCbuild/pythoncore.vcxproj.filters
index bc0f9b034c85de..45427b28ca9fa7 100644
--- a/PCbuild/pythoncore.vcxproj.filters
+++ b/PCbuild/pythoncore.vcxproj.filters
@@ -1199,6 +1199,9 @@
     <ClCompile Include="..\Python\mystrtoul.c">
       <Filter>Python</Filter>
     </ClCompile>
+    <ClCompile Include="..\Python\optimizer.c">
+      <Filter>Python</Filter>
+    </ClCompile>
     <ClCompile Include="..\Python\pathconfig.c">
       <Filter>Python</Filter>
     </ClCompile>
diff --git a/Parser/action_helpers.c b/Parser/action_helpers.c
index 2411da2c705e78..7786124fde82d0 100644
--- a/Parser/action_helpers.c
+++ b/Parser/action_helpers.c
@@ -1350,6 +1350,25 @@ _PyPegen_joined_str(Parser *p, Token* a, asdl_expr_seq* raw_expressions, Token*b
                             p->arena);
 }
 
+expr_ty _PyPegen_decoded_constant_from_token(Parser* p, Token* tok) {
+    Py_ssize_t bsize;
+    char* bstr;
+    if (PyBytes_AsStringAndSize(tok->bytes, &bstr, &bsize) == -1) {
+        return NULL;
+    }
+    PyObject* str = _PyPegen_decode_string(p, 0, bstr, bsize, tok);
+    if (str == NULL) {
+        return NULL;
+    }
+    if (_PyArena_AddPyObject(p->arena, str) < 0) {
+        Py_DECREF(str);
+        return NULL;
+    }
+    return _PyAST_Constant(str, NULL, tok->lineno, tok->col_offset,
+                           tok->end_lineno, tok->end_col_offset,
+                           p->arena);
+}
+
 expr_ty _PyPegen_constant_from_token(Parser* p, Token* tok) {
     char* bstr = PyBytes_AsString(tok->bytes);
     if (bstr == NULL) {
diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index 5d5a05a70ca7ec..cb312796f89e04 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -632,29 +632,38 @@ def visitField(self, field, name, sum=None, prod=None, depth=0):
         self.emit(line % field.name, depth)
         self.emit("return 1;", depth+1)
         self.emit("}", depth)
-        if not field.opt:
+        if field.seq:
             self.emit("if (tmp == NULL) {", depth)
-            message = "required field \\\"%s\\\" missing from %s" % (field.name, name)
-            format = "PyErr_SetString(PyExc_TypeError, \"%s\");"
-            self.emit(format % message, depth+1, reflow=False)
-            self.emit("return 1;", depth+1)
+            self.emit("tmp = PyList_New(0);", depth+1)
+            self.emit("if (tmp == NULL) {", depth+1)
+            self.emit("return 1;", depth+2)
+            self.emit("}", depth+1)
+            self.emit("}", depth)
+            self.emit("{", depth)
         else:
-            self.emit("if (tmp == NULL || tmp == Py_None) {", depth)
-            self.emit("Py_CLEAR(tmp);", depth+1)
-            if self.isNumeric(field):
-                if field.name in self.attribute_special_defaults:
-                    self.emit(
-                        "%s = %s;" % (field.name, self.attribute_special_defaults[field.name]),
-                        depth+1,
-                    )
-                else:
-                    self.emit("%s = 0;" % field.name, depth+1)
-            elif not self.isSimpleType(field):
-                self.emit("%s = NULL;" % field.name, depth+1)
+            if not field.opt:
+                self.emit("if (tmp == NULL) {", depth)
+                message = "required field \\\"%s\\\" missing from %s" % (field.name, name)
+                format = "PyErr_SetString(PyExc_TypeError, \"%s\");"
+                self.emit(format % message, depth+1, reflow=False)
+                self.emit("return 1;", depth+1)
             else:
-                raise TypeError("could not determine the default value for %s" % field.name)
-        self.emit("}", depth)
-        self.emit("else {", depth)
+                self.emit("if (tmp == NULL || tmp == Py_None) {", depth)
+                self.emit("Py_CLEAR(tmp);", depth+1)
+                if self.isNumeric(field):
+                    if field.name in self.attribute_special_defaults:
+                        self.emit(
+                            "%s = %s;" % (field.name, self.attribute_special_defaults[field.name]),
+                            depth+1,
+                        )
+                    else:
+                        self.emit("%s = 0;" % field.name, depth+1)
+                elif not self.isSimpleType(field):
+                    self.emit("%s = NULL;" % field.name, depth+1)
+                else:
+                    raise TypeError("could not determine the default value for %s" % field.name)
+            self.emit("}", depth)
+            self.emit("else {", depth)
 
         self.emit("int res;", depth+1)
         if field.seq:
diff --git a/Parser/parser.c b/Parser/parser.c
index 1705ebd456b5ff..006ee297974a61 100644
--- a/Parser/parser.c
+++ b/Parser/parser.c
@@ -16323,7 +16323,7 @@ fstring_format_spec_rule(Parser *p)
         )
         {
             D(fprintf(stderr, "%*c+ fstring_format_spec[%d-%d]: %s succeeded!\n", p->level, ' ', _mark, p->mark, "FSTRING_MIDDLE"));
-            _res = _PyPegen_constant_from_token ( p , t );
+            _res = _PyPegen_decoded_constant_from_token ( p , t );
             if (_res == NULL && PyErr_Occurred()) {
                 p->error_indicator = 1;
                 p->level--;
diff --git a/Parser/pegen.h b/Parser/pegen.h
index 8800e9f97f5e04..fe13d10e6b83e3 100644
--- a/Parser/pegen.h
+++ b/Parser/pegen.h
@@ -328,6 +328,7 @@ expr_ty _PyPegen_collect_call_seqs(Parser *, asdl_expr_seq *, asdl_seq *,
                      int lineno, int col_offset, int end_lineno,
                      int end_col_offset, PyArena *arena);
 expr_ty _PyPegen_constant_from_token(Parser* p, Token* tok);
+expr_ty _PyPegen_decoded_constant_from_token(Parser* p, Token* tok);
 expr_ty _PyPegen_constant_from_string(Parser* p, Token* tok);
 expr_ty _PyPegen_concatenate_strings(Parser *p, asdl_expr_seq *, int, int, int, int, PyArena *);
 expr_ty _PyPegen_FetchRawForm(Parser *p, int, int, int, int);
diff --git a/Programs/test_frozenmain.h b/Programs/test_frozenmain.h
index cd9d1032629f49..51d65533cbda9f 100644
--- a/Programs/test_frozenmain.h
+++ b/Programs/test_frozenmain.h
@@ -1,38 +1,38 @@
 // Auto-generated by Programs/freeze_test_frozenmain.py
 unsigned char M_test_frozenmain[] = {
     227,0,0,0,0,0,0,0,0,0,0,0,0,8,0,0,
-    0,0,0,0,0,243,162,0,0,0,151,0,100,0,100,1,
+    0,0,0,0,0,243,164,0,0,0,151,0,100,0,100,1,
     108,0,90,0,100,0,100,1,108,1,90,1,2,0,101,2,
     100,2,171,1,0,0,0,0,0,0,1,0,2,0,101,2,
     100,3,101,0,106,6,0,0,0,0,0,0,0,0,0,0,
     0,0,0,0,0,0,0,0,171,2,0,0,0,0,0,0,
     1,0,2,0,101,1,106,8,0,0,0,0,0,0,0,0,
     0,0,0,0,0,0,0,0,0,0,171,0,0,0,0,0,
-    0,0,100,4,25,0,0,0,90,5,100,5,68,0,93,19,
+    0,0,100,4,25,0,0,0,90,5,100,5,68,0,93,20,
     0,0,90,6,2,0,101,2,100,6,101,6,155,0,100,7,
     101,5,101,6,25,0,0,0,155,0,157,4,171,1,0,0,
-    0,0,0,0,1,0,140,21,4,0,121,1,41,8,233,0,
-    0,0,0,78,122,18,70,114,111,122,101,110,32,72,101,108,
-    108,111,32,87,111,114,108,100,122,8,115,121,115,46,97,114,
-    103,118,218,6,99,111,110,102,105,103,41,5,218,12,112,114,
-    111,103,114,97,109,95,110,97,109,101,218,10,101,120,101,99,
-    117,116,97,98,108,101,218,15,117,115,101,95,101,110,118,105,
-    114,111,110,109,101,110,116,218,17,99,111,110,102,105,103,117,
-    114,101,95,99,95,115,116,100,105,111,218,14,98,117,102,102,
-    101,114,101,100,95,115,116,100,105,111,122,7,99,111,110,102,
-    105,103,32,122,2,58,32,41,7,218,3,115,121,115,218,17,
-    95,116,101,115,116,105,110,116,101,114,110,97,108,99,97,112,
-    105,218,5,112,114,105,110,116,218,4,97,114,103,118,218,11,
-    103,101,116,95,99,111,110,102,105,103,115,114,3,0,0,0,
-    218,3,107,101,121,169,0,243,0,0,0,0,250,18,116,101,
-    115,116,95,102,114,111,122,101,110,109,97,105,110,46,112,121,
-    250,8,60,109,111,100,117,108,101,62,114,18,0,0,0,1,
-    0,0,0,115,102,0,0,0,240,3,1,1,1,243,8,0,
-    1,11,219,0,24,225,0,5,208,6,26,212,0,27,217,0,
-    5,128,106,144,35,151,40,145,40,212,0,27,216,9,38,208,
-    9,26,215,9,38,209,9,38,211,9,40,168,24,209,9,50,
-    128,6,240,2,6,12,2,242,0,7,1,42,128,67,241,14,
-    0,5,10,136,71,144,67,144,53,152,2,152,54,160,35,153,
-    59,152,45,208,10,40,213,4,41,241,15,7,1,42,114,16,
-    0,0,0,
+    0,0,0,0,1,0,140,22,0,0,4,0,121,1,41,8,
+    233,0,0,0,0,78,122,18,70,114,111,122,101,110,32,72,
+    101,108,108,111,32,87,111,114,108,100,122,8,115,121,115,46,
+    97,114,103,118,218,6,99,111,110,102,105,103,41,5,218,12,
+    112,114,111,103,114,97,109,95,110,97,109,101,218,10,101,120,
+    101,99,117,116,97,98,108,101,218,15,117,115,101,95,101,110,
+    118,105,114,111,110,109,101,110,116,218,17,99,111,110,102,105,
+    103,117,114,101,95,99,95,115,116,100,105,111,218,14,98,117,
+    102,102,101,114,101,100,95,115,116,100,105,111,122,7,99,111,
+    110,102,105,103,32,122,2,58,32,41,7,218,3,115,121,115,
+    218,17,95,116,101,115,116,105,110,116,101,114,110,97,108,99,
+    97,112,105,218,5,112,114,105,110,116,218,4,97,114,103,118,
+    218,11,103,101,116,95,99,111,110,102,105,103,115,114,3,0,
+    0,0,218,3,107,101,121,169,0,243,0,0,0,0,250,18,
+    116,101,115,116,95,102,114,111,122,101,110,109,97,105,110,46,
+    112,121,250,8,60,109,111,100,117,108,101,62,114,18,0,0,
+    0,1,0,0,0,115,102,0,0,0,240,3,1,1,1,243,
+    8,0,1,11,219,0,24,225,0,5,208,6,26,212,0,27,
+    217,0,5,128,106,144,35,151,40,145,40,212,0,27,216,9,
+    38,208,9,26,215,9,38,209,9,38,211,9,40,168,24,209,
+    9,50,128,6,240,2,6,12,2,242,0,7,1,42,128,67,
+    241,14,0,5,10,136,71,144,67,144,53,152,2,152,54,160,
+    35,153,59,152,45,208,10,40,214,4,41,241,15,7,1,42,
+    114,16,0,0,0,
 };
diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index 030c082a4a6b14..84bce59e271471 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -5760,10 +5760,12 @@ obj2ast_mod(struct ast_state *state, PyObject* obj, mod_ty* out, PyArena* arena)
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from Module");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -5796,10 +5798,12 @@ obj2ast_mod(struct ast_state *state, PyObject* obj, mod_ty* out, PyArena* arena)
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"type_ignores\" missing from Module");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -5844,10 +5848,12 @@ obj2ast_mod(struct ast_state *state, PyObject* obj, mod_ty* out, PyArena* arena)
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from Interactive");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -5922,10 +5928,12 @@ obj2ast_mod(struct ast_state *state, PyObject* obj, mod_ty* out, PyArena* arena)
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"argtypes\" missing from FunctionType");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6119,10 +6127,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from FunctionDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6155,10 +6165,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"decorator_list\" missing from FunctionDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6225,10 +6237,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from FunctionDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6316,10 +6330,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from AsyncFunctionDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6352,10 +6368,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"decorator_list\" missing from AsyncFunctionDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6422,10 +6440,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from AsyncFunctionDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6495,10 +6515,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"bases\" missing from ClassDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6531,10 +6553,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"keywords\" missing from ClassDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6567,10 +6591,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from ClassDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6603,10 +6629,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"decorator_list\" missing from ClassDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6639,10 +6667,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from ClassDef");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6719,10 +6749,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"targets\" missing from Delete");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6770,10 +6802,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"targets\" missing from Assign");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -6872,10 +6906,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from TypeAlias");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7126,10 +7162,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from For");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7162,10 +7200,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"orelse\" missing from For");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7266,10 +7306,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from AsyncFor");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7302,10 +7344,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"orelse\" missing from AsyncFor");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7388,10 +7432,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from While");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7424,10 +7470,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"orelse\" missing from While");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7492,10 +7540,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from If");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7528,10 +7578,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"orelse\" missing from If");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7579,10 +7631,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"items\" missing from With");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7615,10 +7669,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from With");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7683,10 +7739,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"items\" missing from AsyncWith");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7719,10 +7777,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from AsyncWith");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7803,10 +7863,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"cases\" missing from Match");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7903,10 +7965,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from Try");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7939,10 +8003,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"handlers\" missing from Try");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -7975,10 +8041,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"orelse\" missing from Try");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8011,10 +8079,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"finalbody\" missing from Try");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8063,10 +8133,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from TryStar");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8099,10 +8171,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"handlers\" missing from TryStar");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8135,10 +8209,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"orelse\" missing from TryStar");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8171,10 +8247,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"finalbody\" missing from TryStar");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8268,10 +8346,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"names\" missing from Import");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8336,10 +8416,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"names\" missing from ImportFrom");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8402,10 +8484,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"names\" missing from Global");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8451,10 +8535,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"names\" missing from Nonlocal");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -8676,10 +8762,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"values\" missing from BoolOp");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9002,10 +9090,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"keys\" missing from Dict");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9038,10 +9128,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"values\" missing from Dict");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9087,10 +9179,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"elts\" missing from Set");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9154,10 +9248,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"generators\" missing from ListComp");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9221,10 +9317,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"generators\" missing from SetComp");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9306,10 +9404,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"generators\" missing from DictComp");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9373,10 +9473,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"generators\" missing from GeneratorExp");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9531,10 +9633,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"ops\" missing from Compare");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9567,10 +9671,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"comparators\" missing from Compare");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9635,10 +9741,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"args\" missing from Call");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9671,10 +9779,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"keywords\" missing from Call");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -9787,10 +9897,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"values\" missing from JoinedStr");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -10113,10 +10225,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"elts\" missing from List");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -10180,10 +10294,12 @@ obj2ast_expr(struct ast_state *state, PyObject* obj, expr_ty* out, PyArena*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"elts\" missing from Tuple");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -10666,10 +10782,12 @@ obj2ast_comprehension(struct ast_state *state, PyObject* obj, comprehension_ty*
         return 1;
     }
     if (tmp == NULL) {
-        PyErr_SetString(PyExc_TypeError, "required field \"ifs\" missing from comprehension");
-        return 1;
+        tmp = PyList_New(0);
+        if (tmp == NULL) {
+            return 1;
+        }
     }
-    else {
+    {
         int res;
         Py_ssize_t len;
         Py_ssize_t i;
@@ -10855,10 +10973,12 @@ obj2ast_excepthandler(struct ast_state *state, PyObject* obj, excepthandler_ty*
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from ExceptHandler");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -10916,10 +11036,12 @@ obj2ast_arguments(struct ast_state *state, PyObject* obj, arguments_ty* out,
         return 1;
     }
     if (tmp == NULL) {
-        PyErr_SetString(PyExc_TypeError, "required field \"posonlyargs\" missing from arguments");
-        return 1;
+        tmp = PyList_New(0);
+        if (tmp == NULL) {
+            return 1;
+        }
     }
-    else {
+    {
         int res;
         Py_ssize_t len;
         Py_ssize_t i;
@@ -10952,10 +11074,12 @@ obj2ast_arguments(struct ast_state *state, PyObject* obj, arguments_ty* out,
         return 1;
     }
     if (tmp == NULL) {
-        PyErr_SetString(PyExc_TypeError, "required field \"args\" missing from arguments");
-        return 1;
+        tmp = PyList_New(0);
+        if (tmp == NULL) {
+            return 1;
+        }
     }
-    else {
+    {
         int res;
         Py_ssize_t len;
         Py_ssize_t i;
@@ -11005,10 +11129,12 @@ obj2ast_arguments(struct ast_state *state, PyObject* obj, arguments_ty* out,
         return 1;
     }
     if (tmp == NULL) {
-        PyErr_SetString(PyExc_TypeError, "required field \"kwonlyargs\" missing from arguments");
-        return 1;
+        tmp = PyList_New(0);
+        if (tmp == NULL) {
+            return 1;
+        }
     }
-    else {
+    {
         int res;
         Py_ssize_t len;
         Py_ssize_t i;
@@ -11041,10 +11167,12 @@ obj2ast_arguments(struct ast_state *state, PyObject* obj, arguments_ty* out,
         return 1;
     }
     if (tmp == NULL) {
-        PyErr_SetString(PyExc_TypeError, "required field \"kw_defaults\" missing from arguments");
-        return 1;
+        tmp = PyList_New(0);
+        if (tmp == NULL) {
+            return 1;
+        }
     }
-    else {
+    {
         int res;
         Py_ssize_t len;
         Py_ssize_t i;
@@ -11094,10 +11222,12 @@ obj2ast_arguments(struct ast_state *state, PyObject* obj, arguments_ty* out,
         return 1;
     }
     if (tmp == NULL) {
-        PyErr_SetString(PyExc_TypeError, "required field \"defaults\" missing from arguments");
-        return 1;
+        tmp = PyList_New(0);
+        if (tmp == NULL) {
+            return 1;
+        }
     }
-    else {
+    {
         int res;
         Py_ssize_t len;
         Py_ssize_t i;
@@ -11613,10 +11743,12 @@ obj2ast_match_case(struct ast_state *state, PyObject* obj, match_case_ty* out,
         return 1;
     }
     if (tmp == NULL) {
-        PyErr_SetString(PyExc_TypeError, "required field \"body\" missing from match_case");
-        return 1;
+        tmp = PyList_New(0);
+        if (tmp == NULL) {
+            return 1;
+        }
     }
-    else {
+    {
         int res;
         Py_ssize_t len;
         Py_ssize_t i;
@@ -11809,10 +11941,12 @@ obj2ast_pattern(struct ast_state *state, PyObject* obj, pattern_ty* out,
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"patterns\" missing from MatchSequence");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -11860,10 +11994,12 @@ obj2ast_pattern(struct ast_state *state, PyObject* obj, pattern_ty* out,
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"keys\" missing from MatchMapping");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -11896,10 +12032,12 @@ obj2ast_pattern(struct ast_state *state, PyObject* obj, pattern_ty* out,
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"patterns\" missing from MatchMapping");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -11982,10 +12120,12 @@ obj2ast_pattern(struct ast_state *state, PyObject* obj, pattern_ty* out,
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"patterns\" missing from MatchClass");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -12018,10 +12158,12 @@ obj2ast_pattern(struct ast_state *state, PyObject* obj, pattern_ty* out,
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"kwd_attrs\" missing from MatchClass");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -12054,10 +12196,12 @@ obj2ast_pattern(struct ast_state *state, PyObject* obj, pattern_ty* out,
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"kwd_patterns\" missing from MatchClass");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
@@ -12182,10 +12326,12 @@ obj2ast_pattern(struct ast_state *state, PyObject* obj, pattern_ty* out,
             return 1;
         }
         if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"patterns\" missing from MatchOr");
-            return 1;
+            tmp = PyList_New(0);
+            if (tmp == NULL) {
+                return 1;
+            }
         }
-        else {
+        {
             int res;
             Py_ssize_t len;
             Py_ssize_t i;
diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index f142c6ed90bf02..9fcf69b34153f9 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -32,6 +32,7 @@
 #include "dictobject.h"
 #include "pycore_frame.h"
 #include "opcode.h"
+#include "optimizer.h"
 #include "pydtrace.h"
 #include "setobject.h"
 #include "structmember.h"         // struct PyMemberDef, T_OFFSET_EX
@@ -2114,11 +2115,36 @@ dummy_func(
         }
 
         inst(JUMP_BACKWARD, (--)) {
-            assert(oparg < INSTR_OFFSET());
-            JUMPBY(-oparg);
+            _Py_CODEUNIT *here = next_instr - 1;
+            assert(oparg <= INSTR_OFFSET());
+            JUMPBY(1-oparg);
+            #if ENABLE_SPECIALIZATION
+            here[1].cache += (1 << OPTIMIZER_BITS_IN_COUNTER);
+            if (here[1].cache > tstate->interp->optimizer_backedge_threshold) {
+                OBJECT_STAT_INC(optimization_attempts);
+                frame = _PyOptimizer_BackEdge(frame, here, next_instr, stack_pointer);
+                if (frame == NULL) {
+                    frame = cframe.current_frame;
+                    goto error;
+                }
+                here[1].cache &= ((1 << OPTIMIZER_BITS_IN_COUNTER) -1);
+                goto resume_frame;
+            }
+            #endif  /* ENABLE_SPECIALIZATION */
             CHECK_EVAL_BREAKER();
         }
 
+        inst(ENTER_EXECUTOR, (--)) {
+            _PyExecutorObject *executor = (_PyExecutorObject *)frame->f_code->co_executors->executors[oparg];
+            Py_INCREF(executor);
+            frame = executor->execute(executor, frame, stack_pointer);
+            if (frame == NULL) {
+                frame = cframe.current_frame;
+                goto error;
+            }
+            goto resume_frame;
+        }
+
         inst(POP_JUMP_IF_FALSE, (cond -- )) {
             if (Py_IsFalse(cond)) {
                 JUMPBY(oparg);
@@ -3369,7 +3395,7 @@ dummy_func(
         }
 
         inst(INSTRUMENTED_JUMP_BACKWARD, ( -- )) {
-            INSTRUMENTED_JUMP(next_instr-1, next_instr-oparg, PY_MONITORING_EVENT_JUMP);
+            INSTRUMENTED_JUMP(next_instr-1, next_instr+1-oparg, PY_MONITORING_EVENT_JUMP);
             CHECK_EVAL_BREAKER();
         }
 
diff --git a/Python/ceval_macros.h b/Python/ceval_macros.h
index fccf9088cbd131..86a48f68eaf4e0 100644
--- a/Python/ceval_macros.h
+++ b/Python/ceval_macros.h
@@ -300,7 +300,6 @@ GETITEM(PyObject *v, Py_ssize_t i) {
 
 #define INCREMENT_ADAPTIVE_COUNTER(COUNTER)          \
     do {                                             \
-        assert(!ADAPTIVE_COUNTER_IS_MAX((COUNTER))); \
         (COUNTER) += (1 << ADAPTIVE_BACKOFF_BITS);   \
     } while (0);
 
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 7c7afc95b94b37..a47d5ba88a1abc 100644
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -8,7 +8,7 @@
         }
 
         TARGET(RESUME) {
-            #line 137 "Python/bytecodes.c"
+            #line 138 "Python/bytecodes.c"
             assert(tstate->cframe == &cframe);
             assert(frame == cframe.current_frame);
             /* Possibly combine this with eval breaker */
@@ -25,7 +25,7 @@
         }
 
         TARGET(INSTRUMENTED_RESUME) {
-            #line 151 "Python/bytecodes.c"
+            #line 152 "Python/bytecodes.c"
             /* Possible performance enhancement:
              *   We need to check the eval breaker anyway, can we
              * combine the instrument verison check and the eval breaker test?
@@ -57,7 +57,7 @@
 
         TARGET(LOAD_CLOSURE) {
             PyObject *value;
-            #line 179 "Python/bytecodes.c"
+            #line 180 "Python/bytecodes.c"
             /* We keep LOAD_CLOSURE so that the bytecode stays more readable. */
             value = GETLOCAL(oparg);
             if (value == NULL) goto unbound_local_error;
@@ -70,7 +70,7 @@
 
         TARGET(LOAD_FAST_CHECK) {
             PyObject *value;
-            #line 186 "Python/bytecodes.c"
+            #line 187 "Python/bytecodes.c"
             value = GETLOCAL(oparg);
             if (value == NULL) goto unbound_local_error;
             Py_INCREF(value);
@@ -82,7 +82,7 @@
 
         TARGET(LOAD_FAST) {
             PyObject *value;
-            #line 192 "Python/bytecodes.c"
+            #line 193 "Python/bytecodes.c"
             value = GETLOCAL(oparg);
             assert(value != NULL);
             Py_INCREF(value);
@@ -94,7 +94,7 @@
 
         TARGET(LOAD_FAST_AND_CLEAR) {
             PyObject *value;
-            #line 198 "Python/bytecodes.c"
+            #line 199 "Python/bytecodes.c"
             value = GETLOCAL(oparg);
             // do not use SETLOCAL here, it decrefs the old value
             GETLOCAL(oparg) = NULL;
@@ -107,7 +107,7 @@
         TARGET(LOAD_CONST) {
             PREDICTED(LOAD_CONST);
             PyObject *value;
-            #line 204 "Python/bytecodes.c"
+            #line 205 "Python/bytecodes.c"
             value = GETITEM(frame->f_code->co_consts, oparg);
             Py_INCREF(value);
             #line 114 "Python/generated_cases.c.h"
@@ -118,7 +118,7 @@
 
         TARGET(STORE_FAST) {
             PyObject *value = stack_pointer[-1];
-            #line 209 "Python/bytecodes.c"
+            #line 210 "Python/bytecodes.c"
             SETLOCAL(oparg, value);
             #line 124 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -130,7 +130,7 @@
             PyObject *_tmp_2;
             {
                 PyObject *value;
-                #line 192 "Python/bytecodes.c"
+                #line 193 "Python/bytecodes.c"
                 value = GETLOCAL(oparg);
                 assert(value != NULL);
                 Py_INCREF(value);
@@ -140,7 +140,7 @@
             oparg = (next_instr++)->op.arg;
             {
                 PyObject *value;
-                #line 192 "Python/bytecodes.c"
+                #line 193 "Python/bytecodes.c"
                 value = GETLOCAL(oparg);
                 assert(value != NULL);
                 Py_INCREF(value);
@@ -158,7 +158,7 @@
             PyObject *_tmp_2;
             {
                 PyObject *value;
-                #line 192 "Python/bytecodes.c"
+                #line 193 "Python/bytecodes.c"
                 value = GETLOCAL(oparg);
                 assert(value != NULL);
                 Py_INCREF(value);
@@ -168,7 +168,7 @@
             oparg = (next_instr++)->op.arg;
             {
                 PyObject *value;
-                #line 204 "Python/bytecodes.c"
+                #line 205 "Python/bytecodes.c"
                 value = GETITEM(frame->f_code->co_consts, oparg);
                 Py_INCREF(value);
                 #line 175 "Python/generated_cases.c.h"
@@ -184,14 +184,14 @@
             PyObject *_tmp_1 = stack_pointer[-1];
             {
                 PyObject *value = _tmp_1;
-                #line 209 "Python/bytecodes.c"
+                #line 210 "Python/bytecodes.c"
                 SETLOCAL(oparg, value);
                 #line 190 "Python/generated_cases.c.h"
             }
             oparg = (next_instr++)->op.arg;
             {
                 PyObject *value;
-                #line 192 "Python/bytecodes.c"
+                #line 193 "Python/bytecodes.c"
                 value = GETLOCAL(oparg);
                 assert(value != NULL);
                 Py_INCREF(value);
@@ -207,14 +207,14 @@
             PyObject *_tmp_2 = stack_pointer[-2];
             {
                 PyObject *value = _tmp_1;
-                #line 209 "Python/bytecodes.c"
+                #line 210 "Python/bytecodes.c"
                 SETLOCAL(oparg, value);
                 #line 213 "Python/generated_cases.c.h"
             }
             oparg = (next_instr++)->op.arg;
             {
                 PyObject *value = _tmp_2;
-                #line 209 "Python/bytecodes.c"
+                #line 210 "Python/bytecodes.c"
                 SETLOCAL(oparg, value);
                 #line 220 "Python/generated_cases.c.h"
             }
@@ -227,7 +227,7 @@
             PyObject *_tmp_2;
             {
                 PyObject *value;
-                #line 204 "Python/bytecodes.c"
+                #line 205 "Python/bytecodes.c"
                 value = GETITEM(frame->f_code->co_consts, oparg);
                 Py_INCREF(value);
                 #line 234 "Python/generated_cases.c.h"
@@ -236,7 +236,7 @@
             oparg = (next_instr++)->op.arg;
             {
                 PyObject *value;
-                #line 192 "Python/bytecodes.c"
+                #line 193 "Python/bytecodes.c"
                 value = GETLOCAL(oparg);
                 assert(value != NULL);
                 Py_INCREF(value);
@@ -251,7 +251,7 @@
 
         TARGET(POP_TOP) {
             PyObject *value = stack_pointer[-1];
-            #line 219 "Python/bytecodes.c"
+            #line 220 "Python/bytecodes.c"
             #line 256 "Python/generated_cases.c.h"
             Py_DECREF(value);
             STACK_SHRINK(1);
@@ -260,7 +260,7 @@
 
         TARGET(PUSH_NULL) {
             PyObject *res;
-            #line 223 "Python/bytecodes.c"
+            #line 224 "Python/bytecodes.c"
             res = NULL;
             #line 266 "Python/generated_cases.c.h"
             STACK_GROW(1);
@@ -273,13 +273,13 @@
             PyObject *_tmp_2 = stack_pointer[-2];
             {
                 PyObject *value = _tmp_1;
-                #line 219 "Python/bytecodes.c"
+                #line 220 "Python/bytecodes.c"
                 #line 278 "Python/generated_cases.c.h"
                 Py_DECREF(value);
             }
             {
                 PyObject *value = _tmp_2;
-                #line 219 "Python/bytecodes.c"
+                #line 220 "Python/bytecodes.c"
                 #line 284 "Python/generated_cases.c.h"
                 Py_DECREF(value);
             }
@@ -290,7 +290,7 @@
         TARGET(INSTRUMENTED_END_FOR) {
             PyObject *value = stack_pointer[-1];
             PyObject *receiver = stack_pointer[-2];
-            #line 229 "Python/bytecodes.c"
+            #line 230 "Python/bytecodes.c"
             /* Need to create a fake StopIteration error here,
              * to conform to PEP 380 */
             if (PyGen_Check(receiver)) {
@@ -310,7 +310,7 @@
         TARGET(END_SEND) {
             PyObject *value = stack_pointer[-1];
             PyObject *receiver = stack_pointer[-2];
-            #line 242 "Python/bytecodes.c"
+            #line 243 "Python/bytecodes.c"
             Py_DECREF(receiver);
             #line 316 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -321,7 +321,7 @@
         TARGET(INSTRUMENTED_END_SEND) {
             PyObject *value = stack_pointer[-1];
             PyObject *receiver = stack_pointer[-2];
-            #line 246 "Python/bytecodes.c"
+            #line 247 "Python/bytecodes.c"
             if (PyGen_Check(receiver) || PyCoro_CheckExact(receiver)) {
                 PyErr_SetObject(PyExc_StopIteration, value);
                 if (monitor_stop_iteration(tstate, frame, next_instr-1)) {
@@ -339,11 +339,11 @@
         TARGET(UNARY_NEGATIVE) {
             PyObject *value = stack_pointer[-1];
             PyObject *res;
-            #line 257 "Python/bytecodes.c"
+            #line 258 "Python/bytecodes.c"
             res = PyNumber_Negative(value);
             #line 345 "Python/generated_cases.c.h"
             Py_DECREF(value);
-            #line 259 "Python/bytecodes.c"
+            #line 260 "Python/bytecodes.c"
             if (res == NULL) goto pop_1_error;
             #line 349 "Python/generated_cases.c.h"
             stack_pointer[-1] = res;
@@ -353,11 +353,11 @@
         TARGET(UNARY_NOT) {
             PyObject *value = stack_pointer[-1];
             PyObject *res;
-            #line 263 "Python/bytecodes.c"
+            #line 264 "Python/bytecodes.c"
             int err = PyObject_IsTrue(value);
             #line 359 "Python/generated_cases.c.h"
             Py_DECREF(value);
-            #line 265 "Python/bytecodes.c"
+            #line 266 "Python/bytecodes.c"
             if (err < 0) goto pop_1_error;
             if (err == 0) {
                 res = Py_True;
@@ -373,11 +373,11 @@
         TARGET(UNARY_INVERT) {
             PyObject *value = stack_pointer[-1];
             PyObject *res;
-            #line 275 "Python/bytecodes.c"
+            #line 276 "Python/bytecodes.c"
             res = PyNumber_Invert(value);
             #line 379 "Python/generated_cases.c.h"
             Py_DECREF(value);
-            #line 277 "Python/bytecodes.c"
+            #line 278 "Python/bytecodes.c"
             if (res == NULL) goto pop_1_error;
             #line 383 "Python/generated_cases.c.h"
             stack_pointer[-1] = res;
@@ -390,7 +390,7 @@
             {
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
-                #line 293 "Python/bytecodes.c"
+                #line 294 "Python/bytecodes.c"
                 DEOPT_IF(!PyLong_CheckExact(left), BINARY_OP);
                 DEOPT_IF(!PyLong_CheckExact(right), BINARY_OP);
                 #line 397 "Python/generated_cases.c.h"
@@ -401,7 +401,7 @@
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
                 PyObject *res;
-                #line 298 "Python/bytecodes.c"
+                #line 299 "Python/bytecodes.c"
                 STAT_INC(BINARY_OP, hit);
                 res = _PyLong_Multiply((PyLongObject *)left, (PyLongObject *)right);
                 _Py_DECREF_SPECIALIZED(right, (destructor)PyObject_Free);
@@ -422,7 +422,7 @@
             {
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
-                #line 293 "Python/bytecodes.c"
+                #line 294 "Python/bytecodes.c"
                 DEOPT_IF(!PyLong_CheckExact(left), BINARY_OP);
                 DEOPT_IF(!PyLong_CheckExact(right), BINARY_OP);
                 #line 429 "Python/generated_cases.c.h"
@@ -433,7 +433,7 @@
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
                 PyObject *res;
-                #line 306 "Python/bytecodes.c"
+                #line 307 "Python/bytecodes.c"
                 STAT_INC(BINARY_OP, hit);
                 res = _PyLong_Add((PyLongObject *)left, (PyLongObject *)right);
                 _Py_DECREF_SPECIALIZED(right, (destructor)PyObject_Free);
@@ -454,7 +454,7 @@
             {
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
-                #line 293 "Python/bytecodes.c"
+                #line 294 "Python/bytecodes.c"
                 DEOPT_IF(!PyLong_CheckExact(left), BINARY_OP);
                 DEOPT_IF(!PyLong_CheckExact(right), BINARY_OP);
                 #line 461 "Python/generated_cases.c.h"
@@ -465,7 +465,7 @@
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
                 PyObject *res;
-                #line 314 "Python/bytecodes.c"
+                #line 315 "Python/bytecodes.c"
                 STAT_INC(BINARY_OP, hit);
                 res = _PyLong_Subtract((PyLongObject *)left, (PyLongObject *)right);
                 _Py_DECREF_SPECIALIZED(right, (destructor)PyObject_Free);
@@ -486,7 +486,7 @@
             {
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
-                #line 329 "Python/bytecodes.c"
+                #line 330 "Python/bytecodes.c"
                 DEOPT_IF(!PyFloat_CheckExact(left), BINARY_OP);
                 DEOPT_IF(!PyFloat_CheckExact(right), BINARY_OP);
                 #line 493 "Python/generated_cases.c.h"
@@ -497,7 +497,7 @@
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
                 PyObject *res;
-                #line 334 "Python/bytecodes.c"
+                #line 335 "Python/bytecodes.c"
                 STAT_INC(BINARY_OP, hit);
                 double dres =
                     ((PyFloatObject *)left)->ob_fval *
@@ -518,7 +518,7 @@
             {
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
-                #line 329 "Python/bytecodes.c"
+                #line 330 "Python/bytecodes.c"
                 DEOPT_IF(!PyFloat_CheckExact(left), BINARY_OP);
                 DEOPT_IF(!PyFloat_CheckExact(right), BINARY_OP);
                 #line 525 "Python/generated_cases.c.h"
@@ -529,7 +529,7 @@
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
                 PyObject *res;
-                #line 342 "Python/bytecodes.c"
+                #line 343 "Python/bytecodes.c"
                 STAT_INC(BINARY_OP, hit);
                 double dres =
                     ((PyFloatObject *)left)->ob_fval +
@@ -550,7 +550,7 @@
             {
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
-                #line 329 "Python/bytecodes.c"
+                #line 330 "Python/bytecodes.c"
                 DEOPT_IF(!PyFloat_CheckExact(left), BINARY_OP);
                 DEOPT_IF(!PyFloat_CheckExact(right), BINARY_OP);
                 #line 557 "Python/generated_cases.c.h"
@@ -561,7 +561,7 @@
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
                 PyObject *res;
-                #line 350 "Python/bytecodes.c"
+                #line 351 "Python/bytecodes.c"
                 STAT_INC(BINARY_OP, hit);
                 double dres =
                     ((PyFloatObject *)left)->ob_fval -
@@ -582,7 +582,7 @@
             {
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
-                #line 365 "Python/bytecodes.c"
+                #line 366 "Python/bytecodes.c"
                 DEOPT_IF(!PyUnicode_CheckExact(left), BINARY_OP);
                 DEOPT_IF(!PyUnicode_CheckExact(right), BINARY_OP);
                 #line 589 "Python/generated_cases.c.h"
@@ -593,7 +593,7 @@
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
                 PyObject *res;
-                #line 370 "Python/bytecodes.c"
+                #line 371 "Python/bytecodes.c"
                 STAT_INC(BINARY_OP, hit);
                 res = PyUnicode_Concat(left, right);
                 _Py_DECREF_SPECIALIZED(left, _PyUnicode_ExactDealloc);
@@ -614,7 +614,7 @@
             {
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
-                #line 365 "Python/bytecodes.c"
+                #line 366 "Python/bytecodes.c"
                 DEOPT_IF(!PyUnicode_CheckExact(left), BINARY_OP);
                 DEOPT_IF(!PyUnicode_CheckExact(right), BINARY_OP);
                 #line 621 "Python/generated_cases.c.h"
@@ -624,7 +624,7 @@
             {
                 PyObject *right = _tmp_1;
                 PyObject *left = _tmp_2;
-                #line 387 "Python/bytecodes.c"
+                #line 388 "Python/bytecodes.c"
                 _Py_CODEUNIT true_next = next_instr[INLINE_CACHE_ENTRIES_BINARY_OP];
                 assert(true_next.op.code == STORE_FAST ||
                        true_next.op.code == STORE_FAST__LOAD_FAST);
@@ -661,7 +661,7 @@
             PyObject *sub = stack_pointer[-1];
             PyObject *container = stack_pointer[-2];
             PyObject *res;
-            #line 425 "Python/bytecodes.c"
+            #line 426 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyBinarySubscrCache *cache = (_PyBinarySubscrCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -676,7 +676,7 @@
             #line 677 "Python/generated_cases.c.h"
             Py_DECREF(container);
             Py_DECREF(sub);
-            #line 437 "Python/bytecodes.c"
+            #line 438 "Python/bytecodes.c"
             if (res == NULL) goto pop_2_error;
             #line 682 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -690,7 +690,7 @@
             PyObject *start = stack_pointer[-2];
             PyObject *container = stack_pointer[-3];
             PyObject *res;
-            #line 441 "Python/bytecodes.c"
+            #line 442 "Python/bytecodes.c"
             PyObject *slice = _PyBuildSlice_ConsumeRefs(start, stop);
             // Can't use ERROR_IF() here, because we haven't
             // DECREF'ed container yet, and we still own slice.
@@ -714,7 +714,7 @@
             PyObject *start = stack_pointer[-2];
             PyObject *container = stack_pointer[-3];
             PyObject *v = stack_pointer[-4];
-            #line 456 "Python/bytecodes.c"
+            #line 457 "Python/bytecodes.c"
             PyObject *slice = _PyBuildSlice_ConsumeRefs(start, stop);
             int err;
             if (slice == NULL) {
@@ -736,7 +736,7 @@
             PyObject *sub = stack_pointer[-1];
             PyObject *list = stack_pointer[-2];
             PyObject *res;
-            #line 471 "Python/bytecodes.c"
+            #line 472 "Python/bytecodes.c"
             DEOPT_IF(!PyLong_CheckExact(sub), BINARY_SUBSCR);
             DEOPT_IF(!PyList_CheckExact(list), BINARY_SUBSCR);
 
@@ -761,7 +761,7 @@
             PyObject *sub = stack_pointer[-1];
             PyObject *tuple = stack_pointer[-2];
             PyObject *res;
-            #line 487 "Python/bytecodes.c"
+            #line 488 "Python/bytecodes.c"
             DEOPT_IF(!PyLong_CheckExact(sub), BINARY_SUBSCR);
             DEOPT_IF(!PyTuple_CheckExact(tuple), BINARY_SUBSCR);
 
@@ -786,7 +786,7 @@
             PyObject *sub = stack_pointer[-1];
             PyObject *dict = stack_pointer[-2];
             PyObject *res;
-            #line 503 "Python/bytecodes.c"
+            #line 504 "Python/bytecodes.c"
             DEOPT_IF(!PyDict_CheckExact(dict), BINARY_SUBSCR);
             STAT_INC(BINARY_SUBSCR, hit);
             res = PyDict_GetItemWithError(dict, sub);
@@ -797,7 +797,7 @@
             #line 798 "Python/generated_cases.c.h"
                 Py_DECREF(dict);
                 Py_DECREF(sub);
-            #line 511 "Python/bytecodes.c"
+            #line 512 "Python/bytecodes.c"
                 if (true) goto pop_2_error;
             }
             Py_INCREF(res);  // Do this before DECREF'ing dict, sub
@@ -813,7 +813,7 @@
         TARGET(BINARY_SUBSCR_GETITEM) {
             PyObject *sub = stack_pointer[-1];
             PyObject *container = stack_pointer[-2];
-            #line 518 "Python/bytecodes.c"
+            #line 519 "Python/bytecodes.c"
             DEOPT_IF(tstate->interp->eval_frame, BINARY_SUBSCR);
             PyTypeObject *tp = Py_TYPE(container);
             DEOPT_IF(!PyType_HasFeature(tp, Py_TPFLAGS_HEAPTYPE), BINARY_SUBSCR);
@@ -842,7 +842,7 @@
         TARGET(LIST_APPEND) {
             PyObject *v = stack_pointer[-1];
             PyObject *list = stack_pointer[-(2 + (oparg-1))];
-            #line 543 "Python/bytecodes.c"
+            #line 544 "Python/bytecodes.c"
             if (_PyList_AppendTakeRef((PyListObject *)list, v) < 0) goto pop_1_error;
             #line 848 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -853,11 +853,11 @@
         TARGET(SET_ADD) {
             PyObject *v = stack_pointer[-1];
             PyObject *set = stack_pointer[-(2 + (oparg-1))];
-            #line 548 "Python/bytecodes.c"
+            #line 549 "Python/bytecodes.c"
             int err = PySet_Add(set, v);
             #line 859 "Python/generated_cases.c.h"
             Py_DECREF(v);
-            #line 550 "Python/bytecodes.c"
+            #line 551 "Python/bytecodes.c"
             if (err) goto pop_1_error;
             #line 863 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -872,7 +872,7 @@
             PyObject *container = stack_pointer[-2];
             PyObject *v = stack_pointer[-3];
             uint16_t counter = read_u16(&next_instr[0].cache);
-            #line 561 "Python/bytecodes.c"
+            #line 562 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             if (ADAPTIVE_COUNTER_IS_ZERO(counter)) {
                 next_instr--;
@@ -891,7 +891,7 @@
             Py_DECREF(v);
             Py_DECREF(container);
             Py_DECREF(sub);
-            #line 576 "Python/bytecodes.c"
+            #line 577 "Python/bytecodes.c"
             if (err) goto pop_3_error;
             #line 897 "Python/generated_cases.c.h"
             STACK_SHRINK(3);
@@ -903,7 +903,7 @@
             PyObject *sub = stack_pointer[-1];
             PyObject *list = stack_pointer[-2];
             PyObject *value = stack_pointer[-3];
-            #line 580 "Python/bytecodes.c"
+            #line 581 "Python/bytecodes.c"
             DEOPT_IF(!PyLong_CheckExact(sub), STORE_SUBSCR);
             DEOPT_IF(!PyList_CheckExact(list), STORE_SUBSCR);
 
@@ -930,7 +930,7 @@
             PyObject *sub = stack_pointer[-1];
             PyObject *dict = stack_pointer[-2];
             PyObject *value = stack_pointer[-3];
-            #line 599 "Python/bytecodes.c"
+            #line 600 "Python/bytecodes.c"
             DEOPT_IF(!PyDict_CheckExact(dict), STORE_SUBSCR);
             STAT_INC(STORE_SUBSCR, hit);
             int err = _PyDict_SetItem_Take2((PyDictObject *)dict, sub, value);
@@ -945,13 +945,13 @@
         TARGET(DELETE_SUBSCR) {
             PyObject *sub = stack_pointer[-1];
             PyObject *container = stack_pointer[-2];
-            #line 607 "Python/bytecodes.c"
+            #line 608 "Python/bytecodes.c"
             /* del container[sub] */
             int err = PyObject_DelItem(container, sub);
             #line 952 "Python/generated_cases.c.h"
             Py_DECREF(container);
             Py_DECREF(sub);
-            #line 610 "Python/bytecodes.c"
+            #line 611 "Python/bytecodes.c"
             if (err) goto pop_2_error;
             #line 957 "Python/generated_cases.c.h"
             STACK_SHRINK(2);
@@ -961,12 +961,12 @@
         TARGET(CALL_INTRINSIC_1) {
             PyObject *value = stack_pointer[-1];
             PyObject *res;
-            #line 614 "Python/bytecodes.c"
+            #line 615 "Python/bytecodes.c"
             assert(oparg <= MAX_INTRINSIC_1);
             res = _PyIntrinsics_UnaryFunctions[oparg](tstate, value);
             #line 968 "Python/generated_cases.c.h"
             Py_DECREF(value);
-            #line 617 "Python/bytecodes.c"
+            #line 618 "Python/bytecodes.c"
             if (res == NULL) goto pop_1_error;
             #line 972 "Python/generated_cases.c.h"
             stack_pointer[-1] = res;
@@ -977,13 +977,13 @@
             PyObject *value1 = stack_pointer[-1];
             PyObject *value2 = stack_pointer[-2];
             PyObject *res;
-            #line 621 "Python/bytecodes.c"
+            #line 622 "Python/bytecodes.c"
             assert(oparg <= MAX_INTRINSIC_2);
             res = _PyIntrinsics_BinaryFunctions[oparg](tstate, value2, value1);
             #line 984 "Python/generated_cases.c.h"
             Py_DECREF(value2);
             Py_DECREF(value1);
-            #line 624 "Python/bytecodes.c"
+            #line 625 "Python/bytecodes.c"
             if (res == NULL) goto pop_2_error;
             #line 989 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -993,7 +993,7 @@
 
         TARGET(RAISE_VARARGS) {
             PyObject **args = (stack_pointer - oparg);
-            #line 628 "Python/bytecodes.c"
+            #line 629 "Python/bytecodes.c"
             PyObject *cause = NULL, *exc = NULL;
             switch (oparg) {
             case 2:
@@ -1016,7 +1016,7 @@
 
         TARGET(INTERPRETER_EXIT) {
             PyObject *retval = stack_pointer[-1];
-            #line 648 "Python/bytecodes.c"
+            #line 649 "Python/bytecodes.c"
             assert(frame == &entry_frame);
             assert(_PyFrame_IsIncomplete(frame));
             STACK_SHRINK(1);  // Since we're not going to DISPATCH()
@@ -1032,7 +1032,7 @@
 
         TARGET(RETURN_VALUE) {
             PyObject *retval = stack_pointer[-1];
-            #line 661 "Python/bytecodes.c"
+            #line 662 "Python/bytecodes.c"
             STACK_SHRINK(1);
             assert(EMPTY());
             _PyFrame_SetStackPointer(frame, stack_pointer);
@@ -1050,7 +1050,7 @@
 
         TARGET(INSTRUMENTED_RETURN_VALUE) {
             PyObject *retval = stack_pointer[-1];
-            #line 676 "Python/bytecodes.c"
+            #line 677 "Python/bytecodes.c"
             int err = _Py_call_instrumentation_arg(
                     tstate, PY_MONITORING_EVENT_PY_RETURN,
                     frame, next_instr-1, retval);
@@ -1071,7 +1071,7 @@
         }
 
         TARGET(RETURN_CONST) {
-            #line 695 "Python/bytecodes.c"
+            #line 696 "Python/bytecodes.c"
             PyObject *retval = GETITEM(frame->f_code->co_consts, oparg);
             Py_INCREF(retval);
             assert(EMPTY());
@@ -1089,7 +1089,7 @@
         }
 
         TARGET(INSTRUMENTED_RETURN_CONST) {
-            #line 711 "Python/bytecodes.c"
+            #line 712 "Python/bytecodes.c"
             PyObject *retval = GETITEM(frame->f_code->co_consts, oparg);
             int err = _Py_call_instrumentation_arg(
                     tstate, PY_MONITORING_EVENT_PY_RETURN,
@@ -1113,7 +1113,7 @@
         TARGET(GET_AITER) {
             PyObject *obj = stack_pointer[-1];
             PyObject *iter;
-            #line 731 "Python/bytecodes.c"
+            #line 732 "Python/bytecodes.c"
             unaryfunc getter = NULL;
             PyTypeObject *type = Py_TYPE(obj);
 
@@ -1128,14 +1128,14 @@
                               type->tp_name);
             #line 1130 "Python/generated_cases.c.h"
                 Py_DECREF(obj);
-            #line 744 "Python/bytecodes.c"
+            #line 745 "Python/bytecodes.c"
                 if (true) goto pop_1_error;
             }
 
             iter = (*getter)(obj);
             #line 1137 "Python/generated_cases.c.h"
             Py_DECREF(obj);
-            #line 749 "Python/bytecodes.c"
+            #line 750 "Python/bytecodes.c"
             if (iter == NULL) goto pop_1_error;
 
             if (Py_TYPE(iter)->tp_as_async == NULL ||
@@ -1156,7 +1156,7 @@
         TARGET(GET_ANEXT) {
             PyObject *aiter = stack_pointer[-1];
             PyObject *awaitable;
-            #line 764 "Python/bytecodes.c"
+            #line 765 "Python/bytecodes.c"
             unaryfunc getter = NULL;
             PyObject *next_iter = NULL;
             PyTypeObject *type = Py_TYPE(aiter);
@@ -1211,7 +1211,7 @@
             PREDICTED(GET_AWAITABLE);
             PyObject *iterable = stack_pointer[-1];
             PyObject *iter;
-            #line 811 "Python/bytecodes.c"
+            #line 812 "Python/bytecodes.c"
             iter = _PyCoro_GetAwaitableIter(iterable);
 
             if (iter == NULL) {
@@ -1220,7 +1220,7 @@
 
             #line 1222 "Python/generated_cases.c.h"
             Py_DECREF(iterable);
-            #line 818 "Python/bytecodes.c"
+            #line 819 "Python/bytecodes.c"
 
             if (iter != NULL && PyCoro_CheckExact(iter)) {
                 PyObject *yf = _PyGen_yf((PyGenObject*)iter);
@@ -1250,7 +1250,7 @@
             PyObject *v = stack_pointer[-1];
             PyObject *receiver = stack_pointer[-2];
             PyObject *retval;
-            #line 844 "Python/bytecodes.c"
+            #line 845 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PySendCache *cache = (_PySendCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -1306,7 +1306,7 @@
         TARGET(SEND_GEN) {
             PyObject *v = stack_pointer[-1];
             PyObject *receiver = stack_pointer[-2];
-            #line 893 "Python/bytecodes.c"
+            #line 894 "Python/bytecodes.c"
             DEOPT_IF(tstate->interp->eval_frame, SEND);
             PyGenObject *gen = (PyGenObject *)receiver;
             DEOPT_IF(Py_TYPE(gen) != &PyGen_Type &&
@@ -1327,7 +1327,7 @@
 
         TARGET(INSTRUMENTED_YIELD_VALUE) {
             PyObject *retval = stack_pointer[-1];
-            #line 911 "Python/bytecodes.c"
+            #line 912 "Python/bytecodes.c"
             assert(frame != &entry_frame);
             PyGenObject *gen = _PyFrame_GetGenerator(frame);
             gen->gi_frame_state = FRAME_SUSPENDED;
@@ -1349,7 +1349,7 @@
 
         TARGET(YIELD_VALUE) {
             PyObject *retval = stack_pointer[-1];
-            #line 930 "Python/bytecodes.c"
+            #line 931 "Python/bytecodes.c"
             // NOTE: It's important that YIELD_VALUE never raises an exception!
             // The compiler treats any exception raised here as a failed close()
             // or throw() call.
@@ -1370,7 +1370,7 @@
 
         TARGET(POP_EXCEPT) {
             PyObject *exc_value = stack_pointer[-1];
-            #line 948 "Python/bytecodes.c"
+            #line 949 "Python/bytecodes.c"
             _PyErr_StackItem *exc_info = tstate->exc_info;
             Py_XSETREF(exc_info->exc_value, exc_value);
             #line 1377 "Python/generated_cases.c.h"
@@ -1381,7 +1381,7 @@
         TARGET(RERAISE) {
             PyObject *exc = stack_pointer[-1];
             PyObject **values = (stack_pointer - (1 + oparg));
-            #line 953 "Python/bytecodes.c"
+            #line 954 "Python/bytecodes.c"
             assert(oparg >= 0 && oparg <= 2);
             if (oparg) {
                 PyObject *lasti = values[0];
@@ -1405,13 +1405,13 @@
         TARGET(END_ASYNC_FOR) {
             PyObject *exc = stack_pointer[-1];
             PyObject *awaitable = stack_pointer[-2];
-            #line 973 "Python/bytecodes.c"
+            #line 974 "Python/bytecodes.c"
             assert(exc && PyExceptionInstance_Check(exc));
             if (PyErr_GivenExceptionMatches(exc, PyExc_StopAsyncIteration)) {
             #line 1412 "Python/generated_cases.c.h"
                 Py_DECREF(awaitable);
                 Py_DECREF(exc);
-            #line 976 "Python/bytecodes.c"
+            #line 977 "Python/bytecodes.c"
             }
             else {
                 Py_INCREF(exc);
@@ -1429,7 +1429,7 @@
             PyObject *sub_iter = stack_pointer[-3];
             PyObject *none;
             PyObject *value;
-            #line 985 "Python/bytecodes.c"
+            #line 986 "Python/bytecodes.c"
             assert(throwflag);
             assert(exc_value && PyExceptionInstance_Check(exc_value));
             if (PyErr_GivenExceptionMatches(exc_value, PyExc_StopIteration)) {
@@ -1438,7 +1438,7 @@
                 Py_DECREF(sub_iter);
                 Py_DECREF(last_sent_val);
                 Py_DECREF(exc_value);
-            #line 990 "Python/bytecodes.c"
+            #line 991 "Python/bytecodes.c"
                 none = Py_None;
             }
             else {
@@ -1454,7 +1454,7 @@
 
         TARGET(LOAD_ASSERTION_ERROR) {
             PyObject *value;
-            #line 999 "Python/bytecodes.c"
+            #line 1000 "Python/bytecodes.c"
             value = Py_NewRef(PyExc_AssertionError);
             #line 1460 "Python/generated_cases.c.h"
             STACK_GROW(1);
@@ -1464,7 +1464,7 @@
 
         TARGET(LOAD_BUILD_CLASS) {
             PyObject *bc;
-            #line 1003 "Python/bytecodes.c"
+            #line 1004 "Python/bytecodes.c"
             if (PyDict_CheckExact(BUILTINS())) {
                 bc = _PyDict_GetItemWithError(BUILTINS(),
                                               &_Py_ID(__build_class__));
@@ -1494,7 +1494,7 @@
 
         TARGET(STORE_NAME) {
             PyObject *v = stack_pointer[-1];
-            #line 1028 "Python/bytecodes.c"
+            #line 1029 "Python/bytecodes.c"
             PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             PyObject *ns = LOCALS();
             int err;
@@ -1503,7 +1503,7 @@
                               "no locals found when storing %R", name);
             #line 1505 "Python/generated_cases.c.h"
                 Py_DECREF(v);
-            #line 1035 "Python/bytecodes.c"
+            #line 1036 "Python/bytecodes.c"
                 if (true) goto pop_1_error;
             }
             if (PyDict_CheckExact(ns))
@@ -1512,7 +1512,7 @@
                 err = PyObject_SetItem(ns, name, v);
             #line 1514 "Python/generated_cases.c.h"
             Py_DECREF(v);
-            #line 1042 "Python/bytecodes.c"
+            #line 1043 "Python/bytecodes.c"
             if (err) goto pop_1_error;
             #line 1518 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -1520,7 +1520,7 @@
         }
 
         TARGET(DELETE_NAME) {
-            #line 1046 "Python/bytecodes.c"
+            #line 1047 "Python/bytecodes.c"
             PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             PyObject *ns = LOCALS();
             int err;
@@ -1545,7 +1545,7 @@
             PREDICTED(UNPACK_SEQUENCE);
             static_assert(INLINE_CACHE_ENTRIES_UNPACK_SEQUENCE == 1, "incorrect cache size");
             PyObject *seq = stack_pointer[-1];
-            #line 1072 "Python/bytecodes.c"
+            #line 1073 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyUnpackSequenceCache *cache = (_PyUnpackSequenceCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -1560,7 +1560,7 @@
             int res = unpack_iterable(tstate, seq, oparg, -1, top);
             #line 1562 "Python/generated_cases.c.h"
             Py_DECREF(seq);
-            #line 1085 "Python/bytecodes.c"
+            #line 1086 "Python/bytecodes.c"
             if (res == 0) goto pop_1_error;
             #line 1566 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -1572,7 +1572,7 @@
         TARGET(UNPACK_SEQUENCE_TWO_TUPLE) {
             PyObject *seq = stack_pointer[-1];
             PyObject **values = stack_pointer - (1);
-            #line 1089 "Python/bytecodes.c"
+            #line 1090 "Python/bytecodes.c"
             DEOPT_IF(!PyTuple_CheckExact(seq), UNPACK_SEQUENCE);
             DEOPT_IF(PyTuple_GET_SIZE(seq) != 2, UNPACK_SEQUENCE);
             assert(oparg == 2);
@@ -1590,7 +1590,7 @@
         TARGET(UNPACK_SEQUENCE_TUPLE) {
             PyObject *seq = stack_pointer[-1];
             PyObject **values = stack_pointer - (1);
-            #line 1099 "Python/bytecodes.c"
+            #line 1100 "Python/bytecodes.c"
             DEOPT_IF(!PyTuple_CheckExact(seq), UNPACK_SEQUENCE);
             DEOPT_IF(PyTuple_GET_SIZE(seq) != oparg, UNPACK_SEQUENCE);
             STAT_INC(UNPACK_SEQUENCE, hit);
@@ -1609,7 +1609,7 @@
         TARGET(UNPACK_SEQUENCE_LIST) {
             PyObject *seq = stack_pointer[-1];
             PyObject **values = stack_pointer - (1);
-            #line 1110 "Python/bytecodes.c"
+            #line 1111 "Python/bytecodes.c"
             DEOPT_IF(!PyList_CheckExact(seq), UNPACK_SEQUENCE);
             DEOPT_IF(PyList_GET_SIZE(seq) != oparg, UNPACK_SEQUENCE);
             STAT_INC(UNPACK_SEQUENCE, hit);
@@ -1627,13 +1627,13 @@
 
         TARGET(UNPACK_EX) {
             PyObject *seq = stack_pointer[-1];
-            #line 1121 "Python/bytecodes.c"
+            #line 1122 "Python/bytecodes.c"
             int totalargs = 1 + (oparg & 0xFF) + (oparg >> 8);
             PyObject **top = stack_pointer + totalargs - 1;
             int res = unpack_iterable(tstate, seq, oparg & 0xFF, oparg >> 8, top);
             #line 1635 "Python/generated_cases.c.h"
             Py_DECREF(seq);
-            #line 1125 "Python/bytecodes.c"
+            #line 1126 "Python/bytecodes.c"
             if (res == 0) goto pop_1_error;
             #line 1639 "Python/generated_cases.c.h"
             STACK_GROW((oparg & 0xFF) + (oparg >> 8));
@@ -1646,7 +1646,7 @@
             PyObject *owner = stack_pointer[-1];
             PyObject *v = stack_pointer[-2];
             uint16_t counter = read_u16(&next_instr[0].cache);
-            #line 1136 "Python/bytecodes.c"
+            #line 1137 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             if (ADAPTIVE_COUNTER_IS_ZERO(counter)) {
                 PyObject *name = GETITEM(frame->f_code->co_names, oparg);
@@ -1665,7 +1665,7 @@
             #line 1666 "Python/generated_cases.c.h"
             Py_DECREF(v);
             Py_DECREF(owner);
-            #line 1152 "Python/bytecodes.c"
+            #line 1153 "Python/bytecodes.c"
             if (err) goto pop_2_error;
             #line 1671 "Python/generated_cases.c.h"
             STACK_SHRINK(2);
@@ -1675,12 +1675,12 @@
 
         TARGET(DELETE_ATTR) {
             PyObject *owner = stack_pointer[-1];
-            #line 1156 "Python/bytecodes.c"
+            #line 1157 "Python/bytecodes.c"
             PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             int err = PyObject_SetAttr(owner, name, (PyObject *)NULL);
             #line 1682 "Python/generated_cases.c.h"
             Py_DECREF(owner);
-            #line 1159 "Python/bytecodes.c"
+            #line 1160 "Python/bytecodes.c"
             if (err) goto pop_1_error;
             #line 1686 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -1689,12 +1689,12 @@
 
         TARGET(STORE_GLOBAL) {
             PyObject *v = stack_pointer[-1];
-            #line 1163 "Python/bytecodes.c"
+            #line 1164 "Python/bytecodes.c"
             PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             int err = PyDict_SetItem(GLOBALS(), name, v);
             #line 1696 "Python/generated_cases.c.h"
             Py_DECREF(v);
-            #line 1166 "Python/bytecodes.c"
+            #line 1167 "Python/bytecodes.c"
             if (err) goto pop_1_error;
             #line 1700 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -1702,7 +1702,7 @@
         }
 
         TARGET(DELETE_GLOBAL) {
-            #line 1170 "Python/bytecodes.c"
+            #line 1171 "Python/bytecodes.c"
             PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             int err;
             err = PyDict_DelItem(GLOBALS(), name);
@@ -1722,7 +1722,7 @@
             PyObject *_tmp_1;
             {
                 PyObject *locals;
-                #line 1184 "Python/bytecodes.c"
+                #line 1185 "Python/bytecodes.c"
                 locals = LOCALS();
                 if (locals == NULL) {
                     _PyErr_SetString(tstate, PyExc_SystemError,
@@ -1742,7 +1742,7 @@
             PyObject *_tmp_1;
             {
                 PyObject *locals;
-                #line 1184 "Python/bytecodes.c"
+                #line 1185 "Python/bytecodes.c"
                 locals = LOCALS();
                 if (locals == NULL) {
                     _PyErr_SetString(tstate, PyExc_SystemError,
@@ -1756,7 +1756,7 @@
             {
                 PyObject *mod_or_class_dict = _tmp_1;
                 PyObject *v;
-                #line 1196 "Python/bytecodes.c"
+                #line 1197 "Python/bytecodes.c"
                 PyObject *name = GETITEM(frame->f_code->co_names, oparg);
                 if (PyDict_CheckExact(mod_or_class_dict)) {
                     v = PyDict_GetItemWithError(mod_or_class_dict, name);
@@ -1826,7 +1826,7 @@
             {
                 PyObject *mod_or_class_dict = _tmp_1;
                 PyObject *v;
-                #line 1196 "Python/bytecodes.c"
+                #line 1197 "Python/bytecodes.c"
                 PyObject *name = GETITEM(frame->f_code->co_names, oparg);
                 if (PyDict_CheckExact(mod_or_class_dict)) {
                     v = PyDict_GetItemWithError(mod_or_class_dict, name);
@@ -1895,7 +1895,7 @@
             static_assert(INLINE_CACHE_ENTRIES_LOAD_GLOBAL == 4, "incorrect cache size");
             PyObject *null = NULL;
             PyObject *v;
-            #line 1265 "Python/bytecodes.c"
+            #line 1266 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyLoadGlobalCache *cache = (_PyLoadGlobalCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -1961,7 +1961,7 @@
             PyObject *res;
             uint16_t index = read_u16(&next_instr[1].cache);
             uint16_t version = read_u16(&next_instr[2].cache);
-            #line 1319 "Python/bytecodes.c"
+            #line 1320 "Python/bytecodes.c"
             DEOPT_IF(!PyDict_CheckExact(GLOBALS()), LOAD_GLOBAL);
             PyDictObject *dict = (PyDictObject *)GLOBALS();
             DEOPT_IF(dict->ma_keys->dk_version != version, LOAD_GLOBAL);
@@ -1987,7 +1987,7 @@
             uint16_t index = read_u16(&next_instr[1].cache);
             uint16_t mod_version = read_u16(&next_instr[2].cache);
             uint16_t bltn_version = read_u16(&next_instr[3].cache);
-            #line 1332 "Python/bytecodes.c"
+            #line 1333 "Python/bytecodes.c"
             DEOPT_IF(!PyDict_CheckExact(GLOBALS()), LOAD_GLOBAL);
             DEOPT_IF(!PyDict_CheckExact(BUILTINS()), LOAD_GLOBAL);
             PyDictObject *mdict = (PyDictObject *)GLOBALS();
@@ -2012,7 +2012,7 @@
         }
 
         TARGET(DELETE_FAST) {
-            #line 1349 "Python/bytecodes.c"
+            #line 1350 "Python/bytecodes.c"
             PyObject *v = GETLOCAL(oparg);
             if (v == NULL) goto unbound_local_error;
             SETLOCAL(oparg, NULL);
@@ -2021,7 +2021,7 @@
         }
 
         TARGET(MAKE_CELL) {
-            #line 1355 "Python/bytecodes.c"
+            #line 1356 "Python/bytecodes.c"
             // "initial" is probably NULL but not if it's an arg (or set
             // via PyFrame_LocalsToFast() before MAKE_CELL has run).
             PyObject *initial = GETLOCAL(oparg);
@@ -2035,7 +2035,7 @@
         }
 
         TARGET(DELETE_DEREF) {
-            #line 1366 "Python/bytecodes.c"
+            #line 1367 "Python/bytecodes.c"
             PyObject *cell = GETLOCAL(oparg);
             PyObject *oldobj = PyCell_GET(cell);
             // Can't use ERROR_IF here.
@@ -2053,7 +2053,7 @@
         TARGET(LOAD_FROM_DICT_OR_DEREF) {
             PyObject *class_dict = stack_pointer[-1];
             PyObject *value;
-            #line 1379 "Python/bytecodes.c"
+            #line 1380 "Python/bytecodes.c"
             PyObject *name;
             assert(class_dict);
             assert(oparg >= 0 && oparg < frame->f_code->co_nlocalsplus);
@@ -2095,7 +2095,7 @@
 
         TARGET(LOAD_DEREF) {
             PyObject *value;
-            #line 1416 "Python/bytecodes.c"
+            #line 1417 "Python/bytecodes.c"
             PyObject *cell = GETLOCAL(oparg);
             value = PyCell_GET(cell);
             if (value == NULL) {
@@ -2111,7 +2111,7 @@
 
         TARGET(STORE_DEREF) {
             PyObject *v = stack_pointer[-1];
-            #line 1426 "Python/bytecodes.c"
+            #line 1427 "Python/bytecodes.c"
             PyObject *cell = GETLOCAL(oparg);
             PyObject *oldobj = PyCell_GET(cell);
             PyCell_SET(cell, v);
@@ -2122,7 +2122,7 @@
         }
 
         TARGET(COPY_FREE_VARS) {
-            #line 1433 "Python/bytecodes.c"
+            #line 1434 "Python/bytecodes.c"
             /* Copy closure variables to free variables */
             PyCodeObject *co = frame->f_code;
             assert(PyFunction_Check(frame->f_funcobj));
@@ -2140,13 +2140,13 @@
         TARGET(BUILD_STRING) {
             PyObject **pieces = (stack_pointer - oparg);
             PyObject *str;
-            #line 1446 "Python/bytecodes.c"
+            #line 1447 "Python/bytecodes.c"
             str = _PyUnicode_JoinArray(&_Py_STR(empty), pieces, oparg);
             #line 2146 "Python/generated_cases.c.h"
             for (int _i = oparg; --_i >= 0;) {
                 Py_DECREF(pieces[_i]);
             }
-            #line 1448 "Python/bytecodes.c"
+            #line 1449 "Python/bytecodes.c"
             if (str == NULL) { STACK_SHRINK(oparg); goto error; }
             #line 2152 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
@@ -2158,7 +2158,7 @@
         TARGET(BUILD_TUPLE) {
             PyObject **values = (stack_pointer - oparg);
             PyObject *tup;
-            #line 1452 "Python/bytecodes.c"
+            #line 1453 "Python/bytecodes.c"
             tup = _PyTuple_FromArraySteal(values, oparg);
             if (tup == NULL) { STACK_SHRINK(oparg); goto error; }
             #line 2165 "Python/generated_cases.c.h"
@@ -2171,7 +2171,7 @@
         TARGET(BUILD_LIST) {
             PyObject **values = (stack_pointer - oparg);
             PyObject *list;
-            #line 1457 "Python/bytecodes.c"
+            #line 1458 "Python/bytecodes.c"
             list = _PyList_FromArraySteal(values, oparg);
             if (list == NULL) { STACK_SHRINK(oparg); goto error; }
             #line 2178 "Python/generated_cases.c.h"
@@ -2184,7 +2184,7 @@
         TARGET(LIST_EXTEND) {
             PyObject *iterable = stack_pointer[-1];
             PyObject *list = stack_pointer[-(2 + (oparg-1))];
-            #line 1462 "Python/bytecodes.c"
+            #line 1463 "Python/bytecodes.c"
             PyObject *none_val = _PyList_Extend((PyListObject *)list, iterable);
             if (none_val == NULL) {
                 if (_PyErr_ExceptionMatches(tstate, PyExc_TypeError) &&
@@ -2197,7 +2197,7 @@
                 }
             #line 2199 "Python/generated_cases.c.h"
                 Py_DECREF(iterable);
-            #line 1473 "Python/bytecodes.c"
+            #line 1474 "Python/bytecodes.c"
                 if (true) goto pop_1_error;
             }
             assert(Py_IsNone(none_val));
@@ -2210,11 +2210,11 @@
         TARGET(SET_UPDATE) {
             PyObject *iterable = stack_pointer[-1];
             PyObject *set = stack_pointer[-(2 + (oparg-1))];
-            #line 1480 "Python/bytecodes.c"
+            #line 1481 "Python/bytecodes.c"
             int err = _PySet_Update(set, iterable);
             #line 2216 "Python/generated_cases.c.h"
             Py_DECREF(iterable);
-            #line 1482 "Python/bytecodes.c"
+            #line 1483 "Python/bytecodes.c"
             if (err < 0) goto pop_1_error;
             #line 2220 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -2224,7 +2224,7 @@
         TARGET(BUILD_SET) {
             PyObject **values = (stack_pointer - oparg);
             PyObject *set;
-            #line 1486 "Python/bytecodes.c"
+            #line 1487 "Python/bytecodes.c"
             set = PySet_New(NULL);
             if (set == NULL)
                 goto error;
@@ -2249,7 +2249,7 @@
         TARGET(BUILD_MAP) {
             PyObject **values = (stack_pointer - oparg*2);
             PyObject *map;
-            #line 1503 "Python/bytecodes.c"
+            #line 1504 "Python/bytecodes.c"
             map = _PyDict_FromItems(
                     values, 2,
                     values+1, 2,
@@ -2261,7 +2261,7 @@
             for (int _i = oparg*2; --_i >= 0;) {
                 Py_DECREF(values[_i]);
             }
-            #line 1511 "Python/bytecodes.c"
+            #line 1512 "Python/bytecodes.c"
             if (map == NULL) { STACK_SHRINK(oparg*2); goto error; }
             #line 2267 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg*2);
@@ -2271,7 +2271,7 @@
         }
 
         TARGET(SETUP_ANNOTATIONS) {
-            #line 1515 "Python/bytecodes.c"
+            #line 1516 "Python/bytecodes.c"
             int err;
             PyObject *ann_dict;
             if (LOCALS() == NULL) {
@@ -2319,7 +2319,7 @@
             PyObject *keys = stack_pointer[-1];
             PyObject **values = (stack_pointer - (1 + oparg));
             PyObject *map;
-            #line 1557 "Python/bytecodes.c"
+            #line 1558 "Python/bytecodes.c"
             if (!PyTuple_CheckExact(keys) ||
                 PyTuple_GET_SIZE(keys) != (Py_ssize_t)oparg) {
                 _PyErr_SetString(tstate, PyExc_SystemError,
@@ -2334,7 +2334,7 @@
                 Py_DECREF(values[_i]);
             }
             Py_DECREF(keys);
-            #line 1567 "Python/bytecodes.c"
+            #line 1568 "Python/bytecodes.c"
             if (map == NULL) { STACK_SHRINK(oparg); goto pop_1_error; }
             #line 2340 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
@@ -2344,7 +2344,7 @@
 
         TARGET(DICT_UPDATE) {
             PyObject *update = stack_pointer[-1];
-            #line 1571 "Python/bytecodes.c"
+            #line 1572 "Python/bytecodes.c"
             PyObject *dict = PEEK(oparg + 1);  // update is still on the stack
             if (PyDict_Update(dict, update) < 0) {
                 if (_PyErr_ExceptionMatches(tstate, PyExc_AttributeError)) {
@@ -2354,7 +2354,7 @@
                 }
             #line 2356 "Python/generated_cases.c.h"
                 Py_DECREF(update);
-            #line 1579 "Python/bytecodes.c"
+            #line 1580 "Python/bytecodes.c"
                 if (true) goto pop_1_error;
             }
             #line 2361 "Python/generated_cases.c.h"
@@ -2365,14 +2365,14 @@
 
         TARGET(DICT_MERGE) {
             PyObject *update = stack_pointer[-1];
-            #line 1585 "Python/bytecodes.c"
+            #line 1586 "Python/bytecodes.c"
             PyObject *dict = PEEK(oparg + 1);  // update is still on the stack
 
             if (_PyDict_MergeEx(dict, update, 2) < 0) {
                 format_kwargs_error(tstate, PEEK(3 + oparg), update);
             #line 2374 "Python/generated_cases.c.h"
                 Py_DECREF(update);
-            #line 1590 "Python/bytecodes.c"
+            #line 1591 "Python/bytecodes.c"
                 if (true) goto pop_1_error;
             }
             #line 2379 "Python/generated_cases.c.h"
@@ -2385,7 +2385,7 @@
         TARGET(MAP_ADD) {
             PyObject *value = stack_pointer[-1];
             PyObject *key = stack_pointer[-2];
-            #line 1597 "Python/bytecodes.c"
+            #line 1598 "Python/bytecodes.c"
             PyObject *dict = PEEK(oparg + 2);  // key, value are still on the stack
             assert(PyDict_CheckExact(dict));
             /* dict[key] = value */
@@ -2398,7 +2398,7 @@
         }
 
         TARGET(INSTRUMENTED_LOAD_SUPER_ATTR) {
-            #line 1606 "Python/bytecodes.c"
+            #line 1607 "Python/bytecodes.c"
             _PySuperAttrCache *cache = (_PySuperAttrCache *)next_instr;
             // cancel out the decrement that will happen in LOAD_SUPER_ATTR; we
             // don't want to specialize instrumented instructions
@@ -2415,7 +2415,7 @@
             PyObject *global_super = stack_pointer[-3];
             PyObject *res2 = NULL;
             PyObject *res;
-            #line 1620 "Python/bytecodes.c"
+            #line 1621 "Python/bytecodes.c"
             PyObject *name = GETITEM(frame->f_code->co_names, oparg >> 2);
             int load_method = oparg & 1;
             #if ENABLE_SPECIALIZATION
@@ -2461,7 +2461,7 @@
             Py_DECREF(global_super);
             Py_DECREF(class);
             Py_DECREF(self);
-            #line 1662 "Python/bytecodes.c"
+            #line 1663 "Python/bytecodes.c"
             if (super == NULL) goto pop_3_error;
             res = PyObject_GetAttr(super, name);
             Py_DECREF(super);
@@ -2481,7 +2481,7 @@
             PyObject *global_super = stack_pointer[-3];
             PyObject *res2 = NULL;
             PyObject *res;
-            #line 1669 "Python/bytecodes.c"
+            #line 1670 "Python/bytecodes.c"
             assert(!(oparg & 1));
             DEOPT_IF(global_super != (PyObject *)&PySuper_Type, LOAD_SUPER_ATTR);
             DEOPT_IF(!PyType_Check(class), LOAD_SUPER_ATTR);
@@ -2492,7 +2492,7 @@
             Py_DECREF(global_super);
             Py_DECREF(class);
             Py_DECREF(self);
-            #line 1676 "Python/bytecodes.c"
+            #line 1677 "Python/bytecodes.c"
             if (res == NULL) goto pop_3_error;
             #line 2498 "Python/generated_cases.c.h"
             STACK_SHRINK(2);
@@ -2509,7 +2509,7 @@
             PyObject *global_super = stack_pointer[-3];
             PyObject *res2;
             PyObject *res;
-            #line 1680 "Python/bytecodes.c"
+            #line 1681 "Python/bytecodes.c"
             assert(oparg & 1);
             DEOPT_IF(global_super != (PyObject *)&PySuper_Type, LOAD_SUPER_ATTR);
             DEOPT_IF(!PyType_Check(class), LOAD_SUPER_ATTR);
@@ -2546,7 +2546,7 @@
             PyObject *owner = stack_pointer[-1];
             PyObject *res2 = NULL;
             PyObject *res;
-            #line 1719 "Python/bytecodes.c"
+            #line 1720 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyAttrCache *cache = (_PyAttrCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -2582,7 +2582,7 @@
                     */
             #line 2584 "Python/generated_cases.c.h"
                     Py_DECREF(owner);
-            #line 1753 "Python/bytecodes.c"
+            #line 1754 "Python/bytecodes.c"
                     if (meth == NULL) goto pop_1_error;
                     res2 = NULL;
                     res = meth;
@@ -2593,7 +2593,7 @@
                 res = PyObject_GetAttr(owner, name);
             #line 2595 "Python/generated_cases.c.h"
                 Py_DECREF(owner);
-            #line 1762 "Python/bytecodes.c"
+            #line 1763 "Python/bytecodes.c"
                 if (res == NULL) goto pop_1_error;
             }
             #line 2600 "Python/generated_cases.c.h"
@@ -2610,7 +2610,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint16_t index = read_u16(&next_instr[3].cache);
-            #line 1767 "Python/bytecodes.c"
+            #line 1768 "Python/bytecodes.c"
             PyTypeObject *tp = Py_TYPE(owner);
             assert(type_version != 0);
             DEOPT_IF(tp->tp_version_tag != type_version, LOAD_ATTR);
@@ -2638,7 +2638,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint16_t index = read_u16(&next_instr[3].cache);
-            #line 1783 "Python/bytecodes.c"
+            #line 1784 "Python/bytecodes.c"
             DEOPT_IF(!PyModule_CheckExact(owner), LOAD_ATTR);
             PyDictObject *dict = (PyDictObject *)((PyModuleObject *)owner)->md_dict;
             assert(dict != NULL);
@@ -2666,7 +2666,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint16_t index = read_u16(&next_instr[3].cache);
-            #line 1799 "Python/bytecodes.c"
+            #line 1800 "Python/bytecodes.c"
             PyTypeObject *tp = Py_TYPE(owner);
             assert(type_version != 0);
             DEOPT_IF(tp->tp_version_tag != type_version, LOAD_ATTR);
@@ -2708,7 +2708,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint16_t index = read_u16(&next_instr[3].cache);
-            #line 1829 "Python/bytecodes.c"
+            #line 1830 "Python/bytecodes.c"
             PyTypeObject *tp = Py_TYPE(owner);
             assert(type_version != 0);
             DEOPT_IF(tp->tp_version_tag != type_version, LOAD_ATTR);
@@ -2733,7 +2733,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 1842 "Python/bytecodes.c"
+            #line 1843 "Python/bytecodes.c"
 
             DEOPT_IF(!PyType_Check(cls), LOAD_ATTR);
             DEOPT_IF(((PyTypeObject *)cls)->tp_version_tag != type_version,
@@ -2759,7 +2759,7 @@
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint32_t func_version = read_u32(&next_instr[3].cache);
             PyObject *fget = read_obj(&next_instr[5].cache);
-            #line 1857 "Python/bytecodes.c"
+            #line 1858 "Python/bytecodes.c"
             DEOPT_IF(tstate->interp->eval_frame, LOAD_ATTR);
 
             PyTypeObject *cls = Py_TYPE(owner);
@@ -2791,7 +2791,7 @@
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint32_t func_version = read_u32(&next_instr[3].cache);
             PyObject *getattribute = read_obj(&next_instr[5].cache);
-            #line 1883 "Python/bytecodes.c"
+            #line 1884 "Python/bytecodes.c"
             DEOPT_IF(tstate->interp->eval_frame, LOAD_ATTR);
             PyTypeObject *cls = Py_TYPE(owner);
             DEOPT_IF(cls->tp_version_tag != type_version, LOAD_ATTR);
@@ -2825,7 +2825,7 @@
             PyObject *value = stack_pointer[-2];
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint16_t index = read_u16(&next_instr[3].cache);
-            #line 1911 "Python/bytecodes.c"
+            #line 1912 "Python/bytecodes.c"
             PyTypeObject *tp = Py_TYPE(owner);
             assert(type_version != 0);
             DEOPT_IF(tp->tp_version_tag != type_version, STORE_ATTR);
@@ -2854,7 +2854,7 @@
             PyObject *value = stack_pointer[-2];
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint16_t hint = read_u16(&next_instr[3].cache);
-            #line 1931 "Python/bytecodes.c"
+            #line 1932 "Python/bytecodes.c"
             PyTypeObject *tp = Py_TYPE(owner);
             assert(type_version != 0);
             DEOPT_IF(tp->tp_version_tag != type_version, STORE_ATTR);
@@ -2904,7 +2904,7 @@
             PyObject *value = stack_pointer[-2];
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint16_t index = read_u16(&next_instr[3].cache);
-            #line 1972 "Python/bytecodes.c"
+            #line 1973 "Python/bytecodes.c"
             PyTypeObject *tp = Py_TYPE(owner);
             assert(type_version != 0);
             DEOPT_IF(tp->tp_version_tag != type_version, STORE_ATTR);
@@ -2926,7 +2926,7 @@
             PyObject *right = stack_pointer[-1];
             PyObject *left = stack_pointer[-2];
             PyObject *res;
-            #line 1991 "Python/bytecodes.c"
+            #line 1992 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyCompareOpCache *cache = (_PyCompareOpCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -2942,7 +2942,7 @@
             #line 2943 "Python/generated_cases.c.h"
             Py_DECREF(left);
             Py_DECREF(right);
-            #line 2004 "Python/bytecodes.c"
+            #line 2005 "Python/bytecodes.c"
             if (res == NULL) goto pop_2_error;
             #line 2948 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -2955,7 +2955,7 @@
             PyObject *right = stack_pointer[-1];
             PyObject *left = stack_pointer[-2];
             PyObject *res;
-            #line 2008 "Python/bytecodes.c"
+            #line 2009 "Python/bytecodes.c"
             DEOPT_IF(!PyFloat_CheckExact(left), COMPARE_OP);
             DEOPT_IF(!PyFloat_CheckExact(right), COMPARE_OP);
             STAT_INC(COMPARE_OP, hit);
@@ -2977,7 +2977,7 @@
             PyObject *right = stack_pointer[-1];
             PyObject *left = stack_pointer[-2];
             PyObject *res;
-            #line 2022 "Python/bytecodes.c"
+            #line 2023 "Python/bytecodes.c"
             DEOPT_IF(!PyLong_CheckExact(left), COMPARE_OP);
             DEOPT_IF(!PyLong_CheckExact(right), COMPARE_OP);
             DEOPT_IF(!_PyLong_IsCompact((PyLongObject *)left), COMPARE_OP);
@@ -3003,7 +3003,7 @@
             PyObject *right = stack_pointer[-1];
             PyObject *left = stack_pointer[-2];
             PyObject *res;
-            #line 2040 "Python/bytecodes.c"
+            #line 2041 "Python/bytecodes.c"
             DEOPT_IF(!PyUnicode_CheckExact(left), COMPARE_OP);
             DEOPT_IF(!PyUnicode_CheckExact(right), COMPARE_OP);
             STAT_INC(COMPARE_OP, hit);
@@ -3026,12 +3026,12 @@
             PyObject *right = stack_pointer[-1];
             PyObject *left = stack_pointer[-2];
             PyObject *b;
-            #line 2054 "Python/bytecodes.c"
+            #line 2055 "Python/bytecodes.c"
             int res = Py_Is(left, right) ^ oparg;
             #line 3032 "Python/generated_cases.c.h"
             Py_DECREF(left);
             Py_DECREF(right);
-            #line 2056 "Python/bytecodes.c"
+            #line 2057 "Python/bytecodes.c"
             b = res ? Py_True : Py_False;
             #line 3037 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -3043,12 +3043,12 @@
             PyObject *right = stack_pointer[-1];
             PyObject *left = stack_pointer[-2];
             PyObject *b;
-            #line 2060 "Python/bytecodes.c"
+            #line 2061 "Python/bytecodes.c"
             int res = PySequence_Contains(right, left);
             #line 3049 "Python/generated_cases.c.h"
             Py_DECREF(left);
             Py_DECREF(right);
-            #line 2062 "Python/bytecodes.c"
+            #line 2063 "Python/bytecodes.c"
             if (res < 0) goto pop_2_error;
             b = (res ^ oparg) ? Py_True : Py_False;
             #line 3055 "Python/generated_cases.c.h"
@@ -3062,12 +3062,12 @@
             PyObject *exc_value = stack_pointer[-2];
             PyObject *rest;
             PyObject *match;
-            #line 2067 "Python/bytecodes.c"
+            #line 2068 "Python/bytecodes.c"
             if (check_except_star_type_valid(tstate, match_type) < 0) {
             #line 3068 "Python/generated_cases.c.h"
                 Py_DECREF(exc_value);
                 Py_DECREF(match_type);
-            #line 2069 "Python/bytecodes.c"
+            #line 2070 "Python/bytecodes.c"
                 if (true) goto pop_2_error;
             }
 
@@ -3078,7 +3078,7 @@
             #line 3079 "Python/generated_cases.c.h"
             Py_DECREF(exc_value);
             Py_DECREF(match_type);
-            #line 2077 "Python/bytecodes.c"
+            #line 2078 "Python/bytecodes.c"
             if (res < 0) goto pop_2_error;
 
             assert((match == NULL) == (rest == NULL));
@@ -3097,19 +3097,19 @@
             PyObject *right = stack_pointer[-1];
             PyObject *left = stack_pointer[-2];
             PyObject *b;
-            #line 2088 "Python/bytecodes.c"
+            #line 2089 "Python/bytecodes.c"
             assert(PyExceptionInstance_Check(left));
             if (check_except_type_valid(tstate, right) < 0) {
             #line 3104 "Python/generated_cases.c.h"
                  Py_DECREF(right);
-            #line 2091 "Python/bytecodes.c"
+            #line 2092 "Python/bytecodes.c"
                  if (true) goto pop_1_error;
             }
 
             int res = PyErr_GivenExceptionMatches(left, right);
             #line 3111 "Python/generated_cases.c.h"
             Py_DECREF(right);
-            #line 2096 "Python/bytecodes.c"
+            #line 2097 "Python/bytecodes.c"
             b = res ? Py_True : Py_False;
             #line 3115 "Python/generated_cases.c.h"
             stack_pointer[-1] = b;
@@ -3120,13 +3120,13 @@
             PyObject *fromlist = stack_pointer[-1];
             PyObject *level = stack_pointer[-2];
             PyObject *res;
-            #line 2100 "Python/bytecodes.c"
+            #line 2101 "Python/bytecodes.c"
             PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             res = import_name(tstate, frame, name, fromlist, level);
             #line 3127 "Python/generated_cases.c.h"
             Py_DECREF(level);
             Py_DECREF(fromlist);
-            #line 2103 "Python/bytecodes.c"
+            #line 2104 "Python/bytecodes.c"
             if (res == NULL) goto pop_2_error;
             #line 3132 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
@@ -3137,7 +3137,7 @@
         TARGET(IMPORT_FROM) {
             PyObject *from = stack_pointer[-1];
             PyObject *res;
-            #line 2107 "Python/bytecodes.c"
+            #line 2108 "Python/bytecodes.c"
             PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             res = import_from(tstate, from, name);
             if (res == NULL) goto error;
@@ -3148,7 +3148,7 @@
         }
 
         TARGET(JUMP_FORWARD) {
-            #line 2113 "Python/bytecodes.c"
+            #line 2114 "Python/bytecodes.c"
             JUMPBY(oparg);
             #line 3154 "Python/generated_cases.c.h"
             DISPATCH();
@@ -3156,26 +3156,53 @@
 
         TARGET(JUMP_BACKWARD) {
             PREDICTED(JUMP_BACKWARD);
-            #line 2117 "Python/bytecodes.c"
-            assert(oparg < INSTR_OFFSET());
-            JUMPBY(-oparg);
-            #line 3163 "Python/generated_cases.c.h"
+            #line 2118 "Python/bytecodes.c"
+            _Py_CODEUNIT *here = next_instr - 1;
+            assert(oparg <= INSTR_OFFSET());
+            JUMPBY(1-oparg);
+            #if ENABLE_SPECIALIZATION
+            here[1].cache += (1 << OPTIMIZER_BITS_IN_COUNTER);
+            if (here[1].cache > tstate->interp->optimizer_backedge_threshold) {
+                OBJECT_STAT_INC(optimization_attempts);
+                frame = _PyOptimizer_BackEdge(frame, here, next_instr, stack_pointer);
+                if (frame == NULL) {
+                    frame = cframe.current_frame;
+                    goto error;
+                }
+                here[1].cache &= ((1 << OPTIMIZER_BITS_IN_COUNTER) -1);
+                goto resume_frame;
+            }
+            #endif  /* ENABLE_SPECIALIZATION */
+            #line 3177 "Python/generated_cases.c.h"
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
 
+        TARGET(ENTER_EXECUTOR) {
+            #line 2138 "Python/bytecodes.c"
+            _PyExecutorObject *executor = (_PyExecutorObject *)frame->f_code->co_executors->executors[oparg];
+            Py_INCREF(executor);
+            frame = executor->execute(executor, frame, stack_pointer);
+            if (frame == NULL) {
+                frame = cframe.current_frame;
+                goto error;
+            }
+            goto resume_frame;
+            #line 3192 "Python/generated_cases.c.h"
+        }
+
         TARGET(POP_JUMP_IF_FALSE) {
             PREDICTED(POP_JUMP_IF_FALSE);
             PyObject *cond = stack_pointer[-1];
-            #line 2123 "Python/bytecodes.c"
+            #line 2149 "Python/bytecodes.c"
             if (Py_IsFalse(cond)) {
                 JUMPBY(oparg);
             }
             else if (!Py_IsTrue(cond)) {
                 int err = PyObject_IsTrue(cond);
-            #line 3177 "Python/generated_cases.c.h"
+            #line 3204 "Python/generated_cases.c.h"
                 Py_DECREF(cond);
-            #line 2129 "Python/bytecodes.c"
+            #line 2155 "Python/bytecodes.c"
                 if (err == 0) {
                     JUMPBY(oparg);
                 }
@@ -3183,22 +3210,22 @@
                     if (err < 0) goto pop_1_error;
                 }
             }
-            #line 3187 "Python/generated_cases.c.h"
+            #line 3214 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(POP_JUMP_IF_TRUE) {
             PyObject *cond = stack_pointer[-1];
-            #line 2139 "Python/bytecodes.c"
+            #line 2165 "Python/bytecodes.c"
             if (Py_IsTrue(cond)) {
                 JUMPBY(oparg);
             }
             else if (!Py_IsFalse(cond)) {
                 int err = PyObject_IsTrue(cond);
-            #line 3200 "Python/generated_cases.c.h"
+            #line 3227 "Python/generated_cases.c.h"
                 Py_DECREF(cond);
-            #line 2145 "Python/bytecodes.c"
+            #line 2171 "Python/bytecodes.c"
                 if (err > 0) {
                     JUMPBY(oparg);
                 }
@@ -3206,63 +3233,63 @@
                     if (err < 0) goto pop_1_error;
                 }
             }
-            #line 3210 "Python/generated_cases.c.h"
+            #line 3237 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(POP_JUMP_IF_NOT_NONE) {
             PyObject *value = stack_pointer[-1];
-            #line 2155 "Python/bytecodes.c"
+            #line 2181 "Python/bytecodes.c"
             if (!Py_IsNone(value)) {
-            #line 3219 "Python/generated_cases.c.h"
+            #line 3246 "Python/generated_cases.c.h"
                 Py_DECREF(value);
-            #line 2157 "Python/bytecodes.c"
+            #line 2183 "Python/bytecodes.c"
                 JUMPBY(oparg);
             }
-            #line 3224 "Python/generated_cases.c.h"
+            #line 3251 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(POP_JUMP_IF_NONE) {
             PyObject *value = stack_pointer[-1];
-            #line 2162 "Python/bytecodes.c"
+            #line 2188 "Python/bytecodes.c"
             if (Py_IsNone(value)) {
                 JUMPBY(oparg);
             }
             else {
-            #line 3236 "Python/generated_cases.c.h"
+            #line 3263 "Python/generated_cases.c.h"
                 Py_DECREF(value);
-            #line 2167 "Python/bytecodes.c"
+            #line 2193 "Python/bytecodes.c"
             }
-            #line 3240 "Python/generated_cases.c.h"
+            #line 3267 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(JUMP_BACKWARD_NO_INTERRUPT) {
-            #line 2171 "Python/bytecodes.c"
+            #line 2197 "Python/bytecodes.c"
             /* This bytecode is used in the `yield from` or `await` loop.
              * If there is an interrupt, we want it handled in the innermost
              * generator or coroutine, so we deliberately do not check it here.
              * (see bpo-30039).
              */
             JUMPBY(-oparg);
-            #line 3253 "Python/generated_cases.c.h"
+            #line 3280 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(GET_LEN) {
             PyObject *obj = stack_pointer[-1];
             PyObject *len_o;
-            #line 2180 "Python/bytecodes.c"
+            #line 2206 "Python/bytecodes.c"
             // PUSH(len(TOS))
             Py_ssize_t len_i = PyObject_Length(obj);
             if (len_i < 0) goto error;
             len_o = PyLong_FromSsize_t(len_i);
             if (len_o == NULL) goto error;
-            #line 3266 "Python/generated_cases.c.h"
+            #line 3293 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = len_o;
             DISPATCH();
@@ -3273,16 +3300,16 @@
             PyObject *type = stack_pointer[-2];
             PyObject *subject = stack_pointer[-3];
             PyObject *attrs;
-            #line 2188 "Python/bytecodes.c"
+            #line 2214 "Python/bytecodes.c"
             // Pop TOS and TOS1. Set TOS to a tuple of attributes on success, or
             // None on failure.
             assert(PyTuple_CheckExact(names));
             attrs = match_class(tstate, subject, type, oparg, names);
-            #line 3282 "Python/generated_cases.c.h"
+            #line 3309 "Python/generated_cases.c.h"
             Py_DECREF(subject);
             Py_DECREF(type);
             Py_DECREF(names);
-            #line 2193 "Python/bytecodes.c"
+            #line 2219 "Python/bytecodes.c"
             if (attrs) {
                 assert(PyTuple_CheckExact(attrs));  // Success!
             }
@@ -3290,7 +3317,7 @@
                 if (_PyErr_Occurred(tstate)) goto pop_3_error;
                 attrs = Py_None;  // Failure!
             }
-            #line 3294 "Python/generated_cases.c.h"
+            #line 3321 "Python/generated_cases.c.h"
             STACK_SHRINK(2);
             stack_pointer[-1] = attrs;
             DISPATCH();
@@ -3299,10 +3326,10 @@
         TARGET(MATCH_MAPPING) {
             PyObject *subject = stack_pointer[-1];
             PyObject *res;
-            #line 2203 "Python/bytecodes.c"
+            #line 2229 "Python/bytecodes.c"
             int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_MAPPING;
             res = match ? Py_True : Py_False;
-            #line 3306 "Python/generated_cases.c.h"
+            #line 3333 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             PREDICT(POP_JUMP_IF_FALSE);
@@ -3312,10 +3339,10 @@
         TARGET(MATCH_SEQUENCE) {
             PyObject *subject = stack_pointer[-1];
             PyObject *res;
-            #line 2209 "Python/bytecodes.c"
+            #line 2235 "Python/bytecodes.c"
             int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_SEQUENCE;
             res = match ? Py_True : Py_False;
-            #line 3319 "Python/generated_cases.c.h"
+            #line 3346 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             PREDICT(POP_JUMP_IF_FALSE);
@@ -3326,11 +3353,11 @@
             PyObject *keys = stack_pointer[-1];
             PyObject *subject = stack_pointer[-2];
             PyObject *values_or_none;
-            #line 2215 "Python/bytecodes.c"
+            #line 2241 "Python/bytecodes.c"
             // On successful match, PUSH(values). Otherwise, PUSH(None).
             values_or_none = match_keys(tstate, subject, keys);
             if (values_or_none == NULL) goto error;
-            #line 3334 "Python/generated_cases.c.h"
+            #line 3361 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = values_or_none;
             DISPATCH();
@@ -3339,14 +3366,14 @@
         TARGET(GET_ITER) {
             PyObject *iterable = stack_pointer[-1];
             PyObject *iter;
-            #line 2221 "Python/bytecodes.c"
+            #line 2247 "Python/bytecodes.c"
             /* before: [obj]; after [getiter(obj)] */
             iter = PyObject_GetIter(iterable);
-            #line 3346 "Python/generated_cases.c.h"
+            #line 3373 "Python/generated_cases.c.h"
             Py_DECREF(iterable);
-            #line 2224 "Python/bytecodes.c"
+            #line 2250 "Python/bytecodes.c"
             if (iter == NULL) goto pop_1_error;
-            #line 3350 "Python/generated_cases.c.h"
+            #line 3377 "Python/generated_cases.c.h"
             stack_pointer[-1] = iter;
             DISPATCH();
         }
@@ -3354,7 +3381,7 @@
         TARGET(GET_YIELD_FROM_ITER) {
             PyObject *iterable = stack_pointer[-1];
             PyObject *iter;
-            #line 2228 "Python/bytecodes.c"
+            #line 2254 "Python/bytecodes.c"
             /* before: [obj]; after [getiter(obj)] */
             if (PyCoro_CheckExact(iterable)) {
                 /* `iterable` is a coroutine */
@@ -3377,11 +3404,11 @@
                 if (iter == NULL) {
                     goto error;
                 }
-            #line 3381 "Python/generated_cases.c.h"
+            #line 3408 "Python/generated_cases.c.h"
                 Py_DECREF(iterable);
-            #line 2251 "Python/bytecodes.c"
+            #line 2277 "Python/bytecodes.c"
             }
-            #line 3385 "Python/generated_cases.c.h"
+            #line 3412 "Python/generated_cases.c.h"
             stack_pointer[-1] = iter;
             PREDICT(LOAD_CONST);
             DISPATCH();
@@ -3392,7 +3419,7 @@
             static_assert(INLINE_CACHE_ENTRIES_FOR_ITER == 1, "incorrect cache size");
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2270 "Python/bytecodes.c"
+            #line 2296 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyForIterCache *cache = (_PyForIterCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -3423,7 +3450,7 @@
                 DISPATCH();
             }
             // Common case: no jump, leave it to the code generator
-            #line 3427 "Python/generated_cases.c.h"
+            #line 3454 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3431,7 +3458,7 @@
         }
 
         TARGET(INSTRUMENTED_FOR_ITER) {
-            #line 2303 "Python/bytecodes.c"
+            #line 2329 "Python/bytecodes.c"
             _Py_CODEUNIT *here = next_instr-1;
             _Py_CODEUNIT *target;
             PyObject *iter = TOP();
@@ -3457,14 +3484,14 @@
                 target = next_instr + INLINE_CACHE_ENTRIES_FOR_ITER + oparg + 1;
             }
             INSTRUMENTED_JUMP(here, target, PY_MONITORING_EVENT_BRANCH);
-            #line 3461 "Python/generated_cases.c.h"
+            #line 3488 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(FOR_ITER_LIST) {
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2331 "Python/bytecodes.c"
+            #line 2357 "Python/bytecodes.c"
             DEOPT_IF(Py_TYPE(iter) != &PyListIter_Type, FOR_ITER);
             _PyListIterObject *it = (_PyListIterObject *)iter;
             STAT_INC(FOR_ITER, hit);
@@ -3484,7 +3511,7 @@
             DISPATCH();
         end_for_iter_list:
             // Common case: no jump, leave it to the code generator
-            #line 3488 "Python/generated_cases.c.h"
+            #line 3515 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3494,7 +3521,7 @@
         TARGET(FOR_ITER_TUPLE) {
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2353 "Python/bytecodes.c"
+            #line 2379 "Python/bytecodes.c"
             _PyTupleIterObject *it = (_PyTupleIterObject *)iter;
             DEOPT_IF(Py_TYPE(it) != &PyTupleIter_Type, FOR_ITER);
             STAT_INC(FOR_ITER, hit);
@@ -3514,7 +3541,7 @@
             DISPATCH();
         end_for_iter_tuple:
             // Common case: no jump, leave it to the code generator
-            #line 3518 "Python/generated_cases.c.h"
+            #line 3545 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3524,7 +3551,7 @@
         TARGET(FOR_ITER_RANGE) {
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2375 "Python/bytecodes.c"
+            #line 2401 "Python/bytecodes.c"
             _PyRangeIterObject *r = (_PyRangeIterObject *)iter;
             DEOPT_IF(Py_TYPE(r) != &PyRangeIter_Type, FOR_ITER);
             STAT_INC(FOR_ITER, hit);
@@ -3542,7 +3569,7 @@
             if (next == NULL) {
                 goto error;
             }
-            #line 3546 "Python/generated_cases.c.h"
+            #line 3573 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3551,7 +3578,7 @@
 
         TARGET(FOR_ITER_GEN) {
             PyObject *iter = stack_pointer[-1];
-            #line 2395 "Python/bytecodes.c"
+            #line 2421 "Python/bytecodes.c"
             DEOPT_IF(tstate->interp->eval_frame, FOR_ITER);
             PyGenObject *gen = (PyGenObject *)iter;
             DEOPT_IF(Py_TYPE(gen) != &PyGen_Type, FOR_ITER);
@@ -3567,14 +3594,14 @@
             assert(next_instr[oparg].op.code == END_FOR ||
                    next_instr[oparg].op.code == INSTRUMENTED_END_FOR);
             DISPATCH_INLINED(gen_frame);
-            #line 3571 "Python/generated_cases.c.h"
+            #line 3598 "Python/generated_cases.c.h"
         }
 
         TARGET(BEFORE_ASYNC_WITH) {
             PyObject *mgr = stack_pointer[-1];
             PyObject *exit;
             PyObject *res;
-            #line 2413 "Python/bytecodes.c"
+            #line 2439 "Python/bytecodes.c"
             PyObject *enter = _PyObject_LookupSpecial(mgr, &_Py_ID(__aenter__));
             if (enter == NULL) {
                 if (!_PyErr_Occurred(tstate)) {
@@ -3597,16 +3624,16 @@
                 Py_DECREF(enter);
                 goto error;
             }
-            #line 3601 "Python/generated_cases.c.h"
+            #line 3628 "Python/generated_cases.c.h"
             Py_DECREF(mgr);
-            #line 2436 "Python/bytecodes.c"
+            #line 2462 "Python/bytecodes.c"
             res = _PyObject_CallNoArgs(enter);
             Py_DECREF(enter);
             if (res == NULL) {
                 Py_DECREF(exit);
                 if (true) goto pop_1_error;
             }
-            #line 3610 "Python/generated_cases.c.h"
+            #line 3637 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             stack_pointer[-2] = exit;
@@ -3618,7 +3645,7 @@
             PyObject *mgr = stack_pointer[-1];
             PyObject *exit;
             PyObject *res;
-            #line 2446 "Python/bytecodes.c"
+            #line 2472 "Python/bytecodes.c"
             /* pop the context manager, push its __exit__ and the
              * value returned from calling its __enter__
              */
@@ -3644,16 +3671,16 @@
                 Py_DECREF(enter);
                 goto error;
             }
-            #line 3648 "Python/generated_cases.c.h"
+            #line 3675 "Python/generated_cases.c.h"
             Py_DECREF(mgr);
-            #line 2472 "Python/bytecodes.c"
+            #line 2498 "Python/bytecodes.c"
             res = _PyObject_CallNoArgs(enter);
             Py_DECREF(enter);
             if (res == NULL) {
                 Py_DECREF(exit);
                 if (true) goto pop_1_error;
             }
-            #line 3657 "Python/generated_cases.c.h"
+            #line 3684 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             stack_pointer[-2] = exit;
@@ -3665,7 +3692,7 @@
             PyObject *lasti = stack_pointer[-3];
             PyObject *exit_func = stack_pointer[-4];
             PyObject *res;
-            #line 2481 "Python/bytecodes.c"
+            #line 2507 "Python/bytecodes.c"
             /* At the top of the stack are 4 values:
                - val: TOP = exc_info()
                - unused: SECOND = previous exception
@@ -3686,7 +3713,7 @@
             res = PyObject_Vectorcall(exit_func, stack + 1,
                     3 | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL);
             if (res == NULL) goto error;
-            #line 3690 "Python/generated_cases.c.h"
+            #line 3717 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -3695,7 +3722,7 @@
         TARGET(PUSH_EXC_INFO) {
             PyObject *new_exc = stack_pointer[-1];
             PyObject *prev_exc;
-            #line 2504 "Python/bytecodes.c"
+            #line 2530 "Python/bytecodes.c"
             _PyErr_StackItem *exc_info = tstate->exc_info;
             if (exc_info->exc_value != NULL) {
                 prev_exc = exc_info->exc_value;
@@ -3705,7 +3732,7 @@
             }
             assert(PyExceptionInstance_Check(new_exc));
             exc_info->exc_value = Py_NewRef(new_exc);
-            #line 3709 "Python/generated_cases.c.h"
+            #line 3736 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = new_exc;
             stack_pointer[-2] = prev_exc;
@@ -3719,7 +3746,7 @@
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint32_t keys_version = read_u32(&next_instr[3].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 2516 "Python/bytecodes.c"
+            #line 2542 "Python/bytecodes.c"
             /* Cached method object */
             PyTypeObject *self_cls = Py_TYPE(self);
             assert(type_version != 0);
@@ -3736,7 +3763,7 @@
             assert(_PyType_HasFeature(Py_TYPE(res2), Py_TPFLAGS_METHOD_DESCRIPTOR));
             res = self;
             assert(oparg & 1);
-            #line 3740 "Python/generated_cases.c.h"
+            #line 3767 "Python/generated_cases.c.h"
             STACK_GROW(((oparg & 1) ? 1 : 0));
             stack_pointer[-1] = res;
             if (oparg & 1) { stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))] = res2; }
@@ -3750,7 +3777,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 2535 "Python/bytecodes.c"
+            #line 2561 "Python/bytecodes.c"
             PyTypeObject *self_cls = Py_TYPE(self);
             DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR);
             assert(self_cls->tp_dictoffset == 0);
@@ -3760,7 +3787,7 @@
             res2 = Py_NewRef(descr);
             res = self;
             assert(oparg & 1);
-            #line 3764 "Python/generated_cases.c.h"
+            #line 3791 "Python/generated_cases.c.h"
             STACK_GROW(((oparg & 1) ? 1 : 0));
             stack_pointer[-1] = res;
             if (oparg & 1) { stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))] = res2; }
@@ -3774,7 +3801,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 2547 "Python/bytecodes.c"
+            #line 2573 "Python/bytecodes.c"
             PyTypeObject *self_cls = Py_TYPE(self);
             DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR);
             Py_ssize_t dictoffset = self_cls->tp_dictoffset;
@@ -3788,7 +3815,7 @@
             res2 = Py_NewRef(descr);
             res = self;
             assert(oparg & 1);
-            #line 3792 "Python/generated_cases.c.h"
+            #line 3819 "Python/generated_cases.c.h"
             STACK_GROW(((oparg & 1) ? 1 : 0));
             stack_pointer[-1] = res;
             if (oparg & 1) { stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))] = res2; }
@@ -3797,16 +3824,16 @@
         }
 
         TARGET(KW_NAMES) {
-            #line 2563 "Python/bytecodes.c"
+            #line 2589 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg < PyTuple_GET_SIZE(frame->f_code->co_consts));
             kwnames = GETITEM(frame->f_code->co_consts, oparg);
-            #line 3805 "Python/generated_cases.c.h"
+            #line 3832 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_CALL) {
-            #line 2569 "Python/bytecodes.c"
+            #line 2595 "Python/bytecodes.c"
             int is_meth = PEEK(oparg+2) != NULL;
             int total_args = oparg + is_meth;
             PyObject *function = PEEK(total_args + 1);
@@ -3819,7 +3846,7 @@
             _PyCallCache *cache = (_PyCallCache *)next_instr;
             INCREMENT_ADAPTIVE_COUNTER(cache->counter);
             GO_TO_INSTRUCTION(CALL);
-            #line 3823 "Python/generated_cases.c.h"
+            #line 3850 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL) {
@@ -3829,7 +3856,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2614 "Python/bytecodes.c"
+            #line 2640 "Python/bytecodes.c"
             int is_meth = method != NULL;
             int total_args = oparg;
             if (is_meth) {
@@ -3911,7 +3938,7 @@
                 Py_DECREF(args[i]);
             }
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 3915 "Python/generated_cases.c.h"
+            #line 3942 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -3923,7 +3950,7 @@
         TARGET(CALL_BOUND_METHOD_EXACT_ARGS) {
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
-            #line 2702 "Python/bytecodes.c"
+            #line 2728 "Python/bytecodes.c"
             DEOPT_IF(method != NULL, CALL);
             DEOPT_IF(Py_TYPE(callable) != &PyMethod_Type, CALL);
             STAT_INC(CALL, hit);
@@ -3933,7 +3960,7 @@
             PEEK(oparg + 2) = Py_NewRef(meth);  // method
             Py_DECREF(callable);
             GO_TO_INSTRUCTION(CALL_PY_EXACT_ARGS);
-            #line 3937 "Python/generated_cases.c.h"
+            #line 3964 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_PY_EXACT_ARGS) {
@@ -3942,7 +3969,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             uint32_t func_version = read_u32(&next_instr[1].cache);
-            #line 2714 "Python/bytecodes.c"
+            #line 2740 "Python/bytecodes.c"
             assert(kwnames == NULL);
             DEOPT_IF(tstate->interp->eval_frame, CALL);
             int is_meth = method != NULL;
@@ -3968,7 +3995,7 @@
             JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             frame->return_offset = 0;
             DISPATCH_INLINED(new_frame);
-            #line 3972 "Python/generated_cases.c.h"
+            #line 3999 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_PY_WITH_DEFAULTS) {
@@ -3976,7 +4003,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             uint32_t func_version = read_u32(&next_instr[1].cache);
-            #line 2742 "Python/bytecodes.c"
+            #line 2768 "Python/bytecodes.c"
             assert(kwnames == NULL);
             DEOPT_IF(tstate->interp->eval_frame, CALL);
             int is_meth = method != NULL;
@@ -4012,7 +4039,7 @@
             JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             frame->return_offset = 0;
             DISPATCH_INLINED(new_frame);
-            #line 4016 "Python/generated_cases.c.h"
+            #line 4043 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_NO_KW_TYPE_1) {
@@ -4020,7 +4047,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2780 "Python/bytecodes.c"
+            #line 2806 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             DEOPT_IF(null != NULL, CALL);
@@ -4030,7 +4057,7 @@
             res = Py_NewRef(Py_TYPE(obj));
             Py_DECREF(obj);
             Py_DECREF(&PyType_Type);  // I.e., callable
-            #line 4034 "Python/generated_cases.c.h"
+            #line 4061 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4043,7 +4070,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2792 "Python/bytecodes.c"
+            #line 2818 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             DEOPT_IF(null != NULL, CALL);
@@ -4054,7 +4081,7 @@
             Py_DECREF(arg);
             Py_DECREF(&PyUnicode_Type);  // I.e., callable
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4058 "Python/generated_cases.c.h"
+            #line 4085 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4068,7 +4095,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2806 "Python/bytecodes.c"
+            #line 2832 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             DEOPT_IF(null != NULL, CALL);
@@ -4079,7 +4106,7 @@
             Py_DECREF(arg);
             Py_DECREF(&PyTuple_Type);  // I.e., tuple
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4083 "Python/generated_cases.c.h"
+            #line 4110 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4093,7 +4120,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2820 "Python/bytecodes.c"
+            #line 2846 "Python/bytecodes.c"
             int is_meth = method != NULL;
             int total_args = oparg;
             if (is_meth) {
@@ -4115,7 +4142,7 @@
             }
             Py_DECREF(tp);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4119 "Python/generated_cases.c.h"
+            #line 4146 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4129,7 +4156,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2845 "Python/bytecodes.c"
+            #line 2871 "Python/bytecodes.c"
             /* Builtin METH_O functions */
             assert(kwnames == NULL);
             int is_meth = method != NULL;
@@ -4157,7 +4184,7 @@
             Py_DECREF(arg);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4161 "Python/generated_cases.c.h"
+            #line 4188 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4171,7 +4198,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2876 "Python/bytecodes.c"
+            #line 2902 "Python/bytecodes.c"
             /* Builtin METH_FASTCALL functions, without keywords */
             assert(kwnames == NULL);
             int is_meth = method != NULL;
@@ -4203,7 +4230,7 @@
                    'invalid'). In those cases an exception is set, so we must
                    handle it.
                 */
-            #line 4207 "Python/generated_cases.c.h"
+            #line 4234 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4217,7 +4244,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2911 "Python/bytecodes.c"
+            #line 2937 "Python/bytecodes.c"
             /* Builtin METH_FASTCALL | METH_KEYWORDS functions */
             int is_meth = method != NULL;
             int total_args = oparg;
@@ -4249,7 +4276,7 @@
             }
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4253 "Python/generated_cases.c.h"
+            #line 4280 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4263,7 +4290,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2946 "Python/bytecodes.c"
+            #line 2972 "Python/bytecodes.c"
             assert(kwnames == NULL);
             /* len(o) */
             int is_meth = method != NULL;
@@ -4288,7 +4315,7 @@
             Py_DECREF(callable);
             Py_DECREF(arg);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4292 "Python/generated_cases.c.h"
+            #line 4319 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4301,7 +4328,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2973 "Python/bytecodes.c"
+            #line 2999 "Python/bytecodes.c"
             assert(kwnames == NULL);
             /* isinstance(o, o2) */
             int is_meth = method != NULL;
@@ -4328,7 +4355,7 @@
             Py_DECREF(cls);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4332 "Python/generated_cases.c.h"
+            #line 4359 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4340,7 +4367,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *self = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
-            #line 3003 "Python/bytecodes.c"
+            #line 3029 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             assert(method != NULL);
@@ -4358,14 +4385,14 @@
             JUMPBY(INLINE_CACHE_ENTRIES_CALL + 1);
             assert(next_instr[-1].op.code == POP_TOP);
             DISPATCH();
-            #line 4362 "Python/generated_cases.c.h"
+            #line 4389 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_NO_KW_METHOD_DESCRIPTOR_O) {
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3023 "Python/bytecodes.c"
+            #line 3049 "Python/bytecodes.c"
             assert(kwnames == NULL);
             int is_meth = method != NULL;
             int total_args = oparg;
@@ -4396,7 +4423,7 @@
             Py_DECREF(arg);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4400 "Python/generated_cases.c.h"
+            #line 4427 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4409,7 +4436,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3057 "Python/bytecodes.c"
+            #line 3083 "Python/bytecodes.c"
             int is_meth = method != NULL;
             int total_args = oparg;
             if (is_meth) {
@@ -4438,7 +4465,7 @@
             }
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4442 "Python/generated_cases.c.h"
+            #line 4469 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4451,7 +4478,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3089 "Python/bytecodes.c"
+            #line 3115 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 0 || oparg == 1);
             int is_meth = method != NULL;
@@ -4480,7 +4507,7 @@
             Py_DECREF(self);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4484 "Python/generated_cases.c.h"
+            #line 4511 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4493,7 +4520,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3121 "Python/bytecodes.c"
+            #line 3147 "Python/bytecodes.c"
             assert(kwnames == NULL);
             int is_meth = method != NULL;
             int total_args = oparg;
@@ -4521,7 +4548,7 @@
             }
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4525 "Python/generated_cases.c.h"
+            #line 4552 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4531,9 +4558,9 @@
         }
 
         TARGET(INSTRUMENTED_CALL_FUNCTION_EX) {
-            #line 3152 "Python/bytecodes.c"
+            #line 3178 "Python/bytecodes.c"
             GO_TO_INSTRUCTION(CALL_FUNCTION_EX);
-            #line 4537 "Python/generated_cases.c.h"
+            #line 4564 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_FUNCTION_EX) {
@@ -4542,7 +4569,7 @@
             PyObject *callargs = stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))];
             PyObject *func = stack_pointer[-(2 + ((oparg & 1) ? 1 : 0))];
             PyObject *result;
-            #line 3156 "Python/bytecodes.c"
+            #line 3182 "Python/bytecodes.c"
             // DICT_MERGE is called before this opcode if there are kwargs.
             // It converts all dict subtypes in kwargs into regular dicts.
             assert(kwargs == NULL || PyDict_CheckExact(kwargs));
@@ -4604,14 +4631,14 @@
                 }
                 result = PyObject_Call(func, callargs, kwargs);
             }
-            #line 4608 "Python/generated_cases.c.h"
+            #line 4635 "Python/generated_cases.c.h"
             Py_DECREF(func);
             Py_DECREF(callargs);
             Py_XDECREF(kwargs);
-            #line 3218 "Python/bytecodes.c"
+            #line 3244 "Python/bytecodes.c"
             assert(PEEK(3 + (oparg & 1)) == NULL);
             if (result == NULL) { STACK_SHRINK(((oparg & 1) ? 1 : 0)); goto pop_3_error; }
-            #line 4615 "Python/generated_cases.c.h"
+            #line 4642 "Python/generated_cases.c.h"
             STACK_SHRINK(((oparg & 1) ? 1 : 0));
             STACK_SHRINK(2);
             stack_pointer[-1] = result;
@@ -4626,7 +4653,7 @@
             PyObject *kwdefaults = (oparg & MAKE_FUNCTION_KWDEFAULTS) ? stack_pointer[-(1 + ((oparg & MAKE_FUNCTION_CLOSURE) ? 1 : 0) + ((oparg & MAKE_FUNCTION_ANNOTATIONS) ? 1 : 0) + ((oparg & MAKE_FUNCTION_KWDEFAULTS) ? 1 : 0))] : NULL;
             PyObject *defaults = (oparg & MAKE_FUNCTION_DEFAULTS) ? stack_pointer[-(1 + ((oparg & MAKE_FUNCTION_CLOSURE) ? 1 : 0) + ((oparg & MAKE_FUNCTION_ANNOTATIONS) ? 1 : 0) + ((oparg & MAKE_FUNCTION_KWDEFAULTS) ? 1 : 0) + ((oparg & MAKE_FUNCTION_DEFAULTS) ? 1 : 0))] : NULL;
             PyObject *func;
-            #line 3228 "Python/bytecodes.c"
+            #line 3254 "Python/bytecodes.c"
 
             PyFunctionObject *func_obj = (PyFunctionObject *)
                 PyFunction_New(codeobj, GLOBALS());
@@ -4655,14 +4682,14 @@
 
             func_obj->func_version = ((PyCodeObject *)codeobj)->co_version;
             func = (PyObject *)func_obj;
-            #line 4659 "Python/generated_cases.c.h"
+            #line 4686 "Python/generated_cases.c.h"
             STACK_SHRINK(((oparg & MAKE_FUNCTION_DEFAULTS) ? 1 : 0) + ((oparg & MAKE_FUNCTION_KWDEFAULTS) ? 1 : 0) + ((oparg & MAKE_FUNCTION_ANNOTATIONS) ? 1 : 0) + ((oparg & MAKE_FUNCTION_CLOSURE) ? 1 : 0));
             stack_pointer[-1] = func;
             DISPATCH();
         }
 
         TARGET(RETURN_GENERATOR) {
-            #line 3259 "Python/bytecodes.c"
+            #line 3285 "Python/bytecodes.c"
             assert(PyFunction_Check(frame->f_funcobj));
             PyFunctionObject *func = (PyFunctionObject *)frame->f_funcobj;
             PyGenObject *gen = (PyGenObject *)_Py_MakeCoro(func);
@@ -4683,7 +4710,7 @@
             frame = cframe.current_frame = prev;
             _PyFrame_StackPush(frame, (PyObject *)gen);
             goto resume_frame;
-            #line 4687 "Python/generated_cases.c.h"
+            #line 4714 "Python/generated_cases.c.h"
         }
 
         TARGET(BUILD_SLICE) {
@@ -4691,15 +4718,15 @@
             PyObject *stop = stack_pointer[-(1 + ((oparg == 3) ? 1 : 0))];
             PyObject *start = stack_pointer[-(2 + ((oparg == 3) ? 1 : 0))];
             PyObject *slice;
-            #line 3282 "Python/bytecodes.c"
+            #line 3308 "Python/bytecodes.c"
             slice = PySlice_New(start, stop, step);
-            #line 4697 "Python/generated_cases.c.h"
+            #line 4724 "Python/generated_cases.c.h"
             Py_DECREF(start);
             Py_DECREF(stop);
             Py_XDECREF(step);
-            #line 3284 "Python/bytecodes.c"
+            #line 3310 "Python/bytecodes.c"
             if (slice == NULL) { STACK_SHRINK(((oparg == 3) ? 1 : 0)); goto pop_2_error; }
-            #line 4703 "Python/generated_cases.c.h"
+            #line 4730 "Python/generated_cases.c.h"
             STACK_SHRINK(((oparg == 3) ? 1 : 0));
             STACK_SHRINK(1);
             stack_pointer[-1] = slice;
@@ -4710,7 +4737,7 @@
             PyObject *fmt_spec = ((oparg & FVS_MASK) == FVS_HAVE_SPEC) ? stack_pointer[-((((oparg & FVS_MASK) == FVS_HAVE_SPEC) ? 1 : 0))] : NULL;
             PyObject *value = stack_pointer[-(1 + (((oparg & FVS_MASK) == FVS_HAVE_SPEC) ? 1 : 0))];
             PyObject *result;
-            #line 3288 "Python/bytecodes.c"
+            #line 3314 "Python/bytecodes.c"
             /* Handles f-string value formatting. */
             PyObject *(*conv_fn)(PyObject *);
             int which_conversion = oparg & FVC_MASK;
@@ -4745,7 +4772,7 @@
             Py_DECREF(value);
             Py_XDECREF(fmt_spec);
             if (result == NULL) { STACK_SHRINK((((oparg & FVS_MASK) == FVS_HAVE_SPEC) ? 1 : 0)); goto pop_1_error; }
-            #line 4749 "Python/generated_cases.c.h"
+            #line 4776 "Python/generated_cases.c.h"
             STACK_SHRINK((((oparg & FVS_MASK) == FVS_HAVE_SPEC) ? 1 : 0));
             stack_pointer[-1] = result;
             DISPATCH();
@@ -4754,10 +4781,10 @@
         TARGET(COPY) {
             PyObject *bottom = stack_pointer[-(1 + (oparg-1))];
             PyObject *top;
-            #line 3325 "Python/bytecodes.c"
+            #line 3351 "Python/bytecodes.c"
             assert(oparg > 0);
             top = Py_NewRef(bottom);
-            #line 4761 "Python/generated_cases.c.h"
+            #line 4788 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = top;
             DISPATCH();
@@ -4769,7 +4796,7 @@
             PyObject *rhs = stack_pointer[-1];
             PyObject *lhs = stack_pointer[-2];
             PyObject *res;
-            #line 3330 "Python/bytecodes.c"
+            #line 3356 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyBinaryOpCache *cache = (_PyBinaryOpCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -4784,12 +4811,12 @@
             assert((unsigned)oparg < Py_ARRAY_LENGTH(binary_ops));
             assert(binary_ops[oparg]);
             res = binary_ops[oparg](lhs, rhs);
-            #line 4788 "Python/generated_cases.c.h"
+            #line 4815 "Python/generated_cases.c.h"
             Py_DECREF(lhs);
             Py_DECREF(rhs);
-            #line 3345 "Python/bytecodes.c"
+            #line 3371 "Python/bytecodes.c"
             if (res == NULL) goto pop_2_error;
-            #line 4793 "Python/generated_cases.c.h"
+            #line 4820 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
             next_instr += 1;
@@ -4799,16 +4826,16 @@
         TARGET(SWAP) {
             PyObject *top = stack_pointer[-1];
             PyObject *bottom = stack_pointer[-(2 + (oparg-2))];
-            #line 3350 "Python/bytecodes.c"
+            #line 3376 "Python/bytecodes.c"
             assert(oparg >= 2);
-            #line 4805 "Python/generated_cases.c.h"
+            #line 4832 "Python/generated_cases.c.h"
             stack_pointer[-1] = bottom;
             stack_pointer[-(2 + (oparg-2))] = top;
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_INSTRUCTION) {
-            #line 3354 "Python/bytecodes.c"
+            #line 3380 "Python/bytecodes.c"
             int next_opcode = _Py_call_instrumentation_instruction(
                 tstate, frame, next_instr-1);
             if (next_opcode < 0) goto error;
@@ -4820,26 +4847,26 @@
             assert(next_opcode > 0 && next_opcode < 256);
             opcode = next_opcode;
             DISPATCH_GOTO();
-            #line 4824 "Python/generated_cases.c.h"
+            #line 4851 "Python/generated_cases.c.h"
         }
 
         TARGET(INSTRUMENTED_JUMP_FORWARD) {
-            #line 3368 "Python/bytecodes.c"
+            #line 3394 "Python/bytecodes.c"
             INSTRUMENTED_JUMP(next_instr-1, next_instr+oparg, PY_MONITORING_EVENT_JUMP);
-            #line 4830 "Python/generated_cases.c.h"
+            #line 4857 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_JUMP_BACKWARD) {
-            #line 3372 "Python/bytecodes.c"
-            INSTRUMENTED_JUMP(next_instr-1, next_instr-oparg, PY_MONITORING_EVENT_JUMP);
-            #line 4837 "Python/generated_cases.c.h"
+            #line 3398 "Python/bytecodes.c"
+            INSTRUMENTED_JUMP(next_instr-1, next_instr+1-oparg, PY_MONITORING_EVENT_JUMP);
+            #line 4864 "Python/generated_cases.c.h"
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_TRUE) {
-            #line 3377 "Python/bytecodes.c"
+            #line 3403 "Python/bytecodes.c"
             PyObject *cond = POP();
             int err = PyObject_IsTrue(cond);
             Py_DECREF(cond);
@@ -4848,12 +4875,12 @@
             assert(err == 0 || err == 1);
             int offset = err*oparg;
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4852 "Python/generated_cases.c.h"
+            #line 4879 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_FALSE) {
-            #line 3388 "Python/bytecodes.c"
+            #line 3414 "Python/bytecodes.c"
             PyObject *cond = POP();
             int err = PyObject_IsTrue(cond);
             Py_DECREF(cond);
@@ -4862,12 +4889,12 @@
             assert(err == 0 || err == 1);
             int offset = (1-err)*oparg;
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4866 "Python/generated_cases.c.h"
+            #line 4893 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_NONE) {
-            #line 3399 "Python/bytecodes.c"
+            #line 3425 "Python/bytecodes.c"
             PyObject *value = POP();
             _Py_CODEUNIT *here = next_instr-1;
             int offset;
@@ -4879,12 +4906,12 @@
                 offset = 0;
             }
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4883 "Python/generated_cases.c.h"
+            #line 4910 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_NOT_NONE) {
-            #line 3413 "Python/bytecodes.c"
+            #line 3439 "Python/bytecodes.c"
             PyObject *value = POP();
             _Py_CODEUNIT *here = next_instr-1;
             int offset;
@@ -4896,30 +4923,30 @@
                  offset = oparg;
             }
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4900 "Python/generated_cases.c.h"
+            #line 4927 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(EXTENDED_ARG) {
-            #line 3427 "Python/bytecodes.c"
+            #line 3453 "Python/bytecodes.c"
             assert(oparg);
             opcode = next_instr->op.code;
             oparg = oparg << 8 | next_instr->op.arg;
             PRE_DISPATCH_GOTO();
             DISPATCH_GOTO();
-            #line 4911 "Python/generated_cases.c.h"
+            #line 4938 "Python/generated_cases.c.h"
         }
 
         TARGET(CACHE) {
-            #line 3435 "Python/bytecodes.c"
+            #line 3461 "Python/bytecodes.c"
             assert(0 && "Executing a cache.");
             Py_UNREACHABLE();
-            #line 4918 "Python/generated_cases.c.h"
+            #line 4945 "Python/generated_cases.c.h"
         }
 
         TARGET(RESERVED) {
-            #line 3440 "Python/bytecodes.c"
+            #line 3466 "Python/bytecodes.c"
             assert(0 && "Executing RESERVED instruction.");
             Py_UNREACHABLE();
-            #line 4925 "Python/generated_cases.c.h"
+            #line 4952 "Python/generated_cases.c.h"
         }
diff --git a/Python/instrumentation.c b/Python/instrumentation.c
index c70668e8295ae5..c3249463197d9b 100644
--- a/Python/instrumentation.c
+++ b/Python/instrumentation.c
@@ -256,8 +256,8 @@ compute_line(PyCodeObject *code, int offset, int8_t line_delta)
     return PyCode_Addr2Line(code, offset * sizeof(_Py_CODEUNIT));
 }
 
-static int
-instruction_length(PyCodeObject *code, int offset)
+int
+_PyInstruction_GetLength(PyCodeObject *code, int offset)
 {
     int opcode = _PyCode_CODE(code)[offset].op.code;
     assert(opcode != 0);
@@ -395,7 +395,7 @@ dump_instrumentation_data(PyCodeObject *code, int star, FILE*out)
     dump_monitors("Active", data->active_monitors, out);
     int code_len = (int)Py_SIZE(code);
     bool starred = false;
-    for (int i = 0; i < code_len; i += instruction_length(code, i)) {
+    for (int i = 0; i < code_len; i += _PyInstruction_GetLength(code, i)) {
         _Py_CODEUNIT *instr = &_PyCode_CODE(code)[i];
         int opcode = instr->op.code;
         if (i == star) {
@@ -520,7 +520,7 @@ sanity_check_instrumentation(PyCodeObject *code)
                 CHECK(local_tools == 0xff);
             }
         }
-        i += instruction_length(code, i);
+        i += _PyInstruction_GetLength(code, i);
         assert(i <= code_len);
     }
 }
@@ -1291,7 +1291,7 @@ initialize_lines(PyCodeObject *code)
         int opcode = _Py_GetBaseOpcode(code, i);
         int line = _PyCode_CheckLineNumber(i*(int)sizeof(_Py_CODEUNIT), &range);
         line_data[i].line_delta = compute_line_delta(code, i, line);
-        int length = instruction_length(code, i);
+        int length = _PyInstruction_GetLength(code, i);
         switch (opcode) {
             case END_ASYNC_FOR:
             case END_FOR:
@@ -1332,7 +1332,7 @@ initialize_lines(PyCodeObject *code)
             opcode = _Py_GetBaseOpcode(code, i);
         }
         oparg = (oparg << 8) | _PyCode_CODE(code)[i].op.arg;
-        i += instruction_length(code, i);
+        i += _PyInstruction_GetLength(code, i);
         int target = -1;
         switch (opcode) {
             case POP_JUMP_IF_FALSE:
@@ -1504,7 +1504,6 @@ is_super_instruction(uint8_t opcode) {
 int
 _Py_Instrument(PyCodeObject *code, PyInterpreterState *interp)
 {
-
     if (is_version_up_to_date(code, interp)) {
         assert(
             interp->monitoring_version == 0 ||
@@ -1541,7 +1540,7 @@ _Py_Instrument(PyCodeObject *code, PyInterpreterState *interp)
         return 0;
     }
     /* Insert instrumentation */
-    for (int i = 0; i < code_len; i+= instruction_length(code, i)) {
+    for (int i = 0; i < code_len; i+= _PyInstruction_GetLength(code, i)) {
         _Py_CODEUNIT *instr = &_PyCode_CODE(code)[i];
         if (is_super_instruction(instr->op.code)) {
             instr->op.code = _PyOpcode_Deopt[instr->op.code];
@@ -1582,20 +1581,20 @@ _Py_Instrument(PyCodeObject *code, PyInterpreterState *interp)
                     remove_line_tools(code, i, removed_line_tools);
                 }
             }
-            i += instruction_length(code, i);
+            i += _PyInstruction_GetLength(code, i);
         }
     }
     if (removed_per_instruction_tools) {
         for (int i = code->_co_firsttraceable; i < code_len;) {
             int opcode = _Py_GetBaseOpcode(code, i);
             if (opcode == RESUME || opcode == END_FOR) {
-                i += instruction_length(code, i);
+                i += _PyInstruction_GetLength(code, i);
                 continue;
             }
             if (removed_per_instruction_tools) {
                 remove_per_instruction_tools(code, i, removed_per_instruction_tools);
             }
-            i += instruction_length(code, i);
+            i += _PyInstruction_GetLength(code, i);
         }
     }
 
@@ -1610,20 +1609,20 @@ _Py_Instrument(PyCodeObject *code, PyInterpreterState *interp)
                     add_line_tools(code, i, new_line_tools);
                 }
             }
-            i += instruction_length(code, i);
+            i += _PyInstruction_GetLength(code, i);
         }
     }
     if (new_per_instruction_tools) {
         for (int i = code->_co_firsttraceable; i < code_len;) {
             int opcode = _Py_GetBaseOpcode(code, i);
             if (opcode == RESUME || opcode == END_FOR) {
-                i += instruction_length(code, i);
+                i += _PyInstruction_GetLength(code, i);
                 continue;
             }
             if (new_per_instruction_tools) {
                 add_per_instruction_tools(code, i, new_per_instruction_tools);
             }
-            i += instruction_length(code, i);
+            i += _PyInstruction_GetLength(code, i);
         }
     }
 #ifdef INSTRUMENT_DEBUG
diff --git a/Python/marshal.c b/Python/marshal.c
index 208996b05fc484..6439503d2c6879 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -625,6 +625,10 @@ w_clear_refs(WFILE *wf)
 }
 
 /* version currently has no effect for writing ints. */
+/* Note that while the documentation states that this function
+ * can error, currently it never does. Setting an exception in
+ * this function should be regarded as an API-breaking change.
+ */
 void
 PyMarshal_WriteLongToFile(long x, FILE *fp, int version)
 {
diff --git a/Python/opcode_metadata.h b/Python/opcode_metadata.h
index 2316f8dc29304f..8c0ba7d7f43a76 100644
--- a/Python/opcode_metadata.h
+++ b/Python/opcode_metadata.h
@@ -265,6 +265,8 @@ _PyOpcode_num_popped(int opcode, int oparg, bool jump) {
             return 0;
         case JUMP_BACKWARD:
             return 0;
+        case ENTER_EXECUTOR:
+            return 0;
         case POP_JUMP_IF_FALSE:
             return 1;
         case POP_JUMP_IF_TRUE:
@@ -661,6 +663,8 @@ _PyOpcode_num_pushed(int opcode, int oparg, bool jump) {
             return 0;
         case JUMP_BACKWARD:
             return 0;
+        case ENTER_EXECUTOR:
+            return 0;
         case POP_JUMP_IF_FALSE:
             return 0;
         case POP_JUMP_IF_TRUE:
@@ -933,6 +937,7 @@ const struct opcode_metadata _PyOpcode_opcode_metadata[256] = {
     [IMPORT_FROM] = { true, INSTR_FMT_IB },
     [JUMP_FORWARD] = { true, INSTR_FMT_IB },
     [JUMP_BACKWARD] = { true, INSTR_FMT_IB },
+    [ENTER_EXECUTOR] = { true, INSTR_FMT_IB },
     [POP_JUMP_IF_FALSE] = { true, INSTR_FMT_IB },
     [POP_JUMP_IF_TRUE] = { true, INSTR_FMT_IB },
     [POP_JUMP_IF_NOT_NONE] = { true, INSTR_FMT_IB },
diff --git a/Python/opcode_targets.h b/Python/opcode_targets.h
index 3add06362711c9..9c46f4816369cf 100644
--- a/Python/opcode_targets.h
+++ b/Python/opcode_targets.h
@@ -229,7 +229,7 @@ static void *opcode_targets[256] = {
     &&_unknown_opcode,
     &&_unknown_opcode,
     &&_unknown_opcode,
-    &&_unknown_opcode,
+    &&TARGET_ENTER_EXECUTOR,
     &&_unknown_opcode,
     &&_unknown_opcode,
     &&_unknown_opcode,
diff --git a/Python/optimizer.c b/Python/optimizer.c
new file mode 100644
index 00000000000000..f29e072410e5ed
--- /dev/null
+++ b/Python/optimizer.c
@@ -0,0 +1,254 @@
+
+#include "Python.h"
+#include "opcode.h"
+#include "pycore_interp.h"
+#include "pycore_opcode.h"
+#include "pycore_pystate.h"
+#include "cpython/optimizer.h"
+#include <stdbool.h>
+#include <stdint.h>
+#include <stddef.h>
+
+/* Returns the index of the next space, or -1 if there is no
+ * more space. Doesn't set an exception. */
+static int32_t
+get_next_free_in_executor_array(PyCodeObject *code)
+{
+    _PyExecutorArray *old = code->co_executors;
+    int size = 0;
+    int capacity = 0;
+    if (old != NULL) {
+        size = old->size;
+        capacity = old->capacity;
+        if (capacity >= 256) {
+            return -1;
+        }
+    }
+    assert(size <= capacity);
+    if (size == capacity) {
+        /* Array is full. Grow array */
+        int new_capacity = capacity ? capacity * 2 : 4;
+        _PyExecutorArray *new = PyMem_Realloc(
+            old,
+            offsetof(_PyExecutorArray, executors) +
+            new_capacity * sizeof(_PyExecutorObject *));
+        if (new == NULL) {
+            return -1;
+        }
+        new->capacity = new_capacity;
+        new->size = size;
+        code->co_executors = new;
+    }
+    assert(size < code->co_executors->capacity);
+    code->co_executors->size++;
+    return size;
+}
+
+static void
+insert_executor(PyCodeObject *code, _Py_CODEUNIT *instr, int index, _PyExecutorObject *executor)
+{
+    if (instr->op.code == ENTER_EXECUTOR) {
+        assert(index == instr->op.arg);
+        _PyExecutorObject *old = code->co_executors->executors[index];
+        executor->vm_data.opcode = old->vm_data.opcode;
+        executor->vm_data.oparg = old->vm_data.oparg;
+        old->vm_data.opcode = 0;
+        Py_INCREF(executor);
+        code->co_executors->executors[index] = executor;
+        Py_DECREF(old);
+    }
+    else {
+        Py_INCREF(executor);
+        executor->vm_data.opcode = instr->op.code;
+        executor->vm_data.oparg = instr->op.arg;
+        code->co_executors->executors[index] = executor;
+        assert(index < 256);
+        instr->op.code = ENTER_EXECUTOR;
+        instr->op.arg = index;
+    }
+    return;
+}
+
+static int
+get_executor_index(PyCodeObject *code, _Py_CODEUNIT *instr)
+{
+    if (instr->op.code == ENTER_EXECUTOR) {
+        return instr->op.arg;
+    }
+    else {
+        return get_next_free_in_executor_array(code);
+    }
+}
+
+int
+PyUnstable_Replace_Executor(PyCodeObject *code, _Py_CODEUNIT *instr, _PyExecutorObject *new)
+{
+    if (instr->op.code != ENTER_EXECUTOR) {
+        PyErr_Format(PyExc_ValueError, "No executor to replace");
+        return -1;
+    }
+    int index = get_executor_index(code, instr);
+    assert(index >= 0);
+    insert_executor(code, instr, index, new);
+    return 0;
+}
+
+static _PyExecutorObject *
+error_optimize(
+    _PyOptimizerObject* self,
+    PyCodeObject *code,
+    _Py_CODEUNIT *instr)
+{
+    PyErr_Format(PyExc_SystemError, "Should never call error_optimize");
+    return NULL;
+}
+
+static PyTypeObject DefaultOptimizer_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    .tp_name = "noop_optimizer",
+    .tp_basicsize = sizeof(_PyOptimizerObject),
+    .tp_itemsize = 0,
+    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
+};
+
+_PyOptimizerObject _PyOptimizer_Default = {
+    PyObject_HEAD_INIT(&DefaultOptimizer_Type)
+    .optimize = error_optimize,
+    .resume_threshold = UINT16_MAX,
+    .backedge_threshold = UINT16_MAX,
+};
+
+_PyOptimizerObject *
+PyUnstable_GetOptimizer(void)
+{
+    PyInterpreterState *interp = PyInterpreterState_Get();
+    if (interp->optimizer == &_PyOptimizer_Default) {
+        return NULL;
+    }
+    Py_INCREF(interp->optimizer);
+    return interp->optimizer;
+}
+
+void
+PyUnstable_SetOptimizer(_PyOptimizerObject *optimizer)
+{
+    PyInterpreterState *interp = PyInterpreterState_Get();
+    if (optimizer == NULL) {
+        optimizer = &_PyOptimizer_Default;
+    }
+    _PyOptimizerObject *old = interp->optimizer;
+    Py_INCREF(optimizer);
+    interp->optimizer = optimizer;
+    interp->optimizer_backedge_threshold = optimizer->backedge_threshold;
+    interp->optimizer_resume_threshold = optimizer->resume_threshold;
+    Py_DECREF(old);
+}
+
+_PyInterpreterFrame *
+_PyOptimizer_BackEdge(_PyInterpreterFrame *frame, _Py_CODEUNIT *src, _Py_CODEUNIT *dest, PyObject **stack_pointer)
+{
+    PyInterpreterState *interp = PyInterpreterState_Get();
+    int index = get_executor_index(frame->f_code, src);
+    if (index < 0) {
+        _PyFrame_SetStackPointer(frame, stack_pointer);
+        return frame;
+    }
+    _PyOptimizerObject *opt = interp->optimizer;
+    _PyExecutorObject *executor = opt->optimize(opt, frame->f_code, dest);
+    if (executor == NULL) {
+        return NULL;
+    }
+    insert_executor(frame->f_code, src, index, executor);
+    return executor->execute(executor, frame, stack_pointer);
+}
+
+
+/** Test support **/
+
+
+typedef struct {
+    _PyOptimizerObject base;
+    int64_t count;
+} _PyCounterOptimizerObject;
+
+typedef struct {
+    _PyExecutorObject executor;
+    _PyCounterOptimizerObject *optimizer;
+    _Py_CODEUNIT *next_instr;
+} _PyCounterExecutorObject;
+
+static void
+counter_dealloc(_PyCounterExecutorObject *self) {
+    Py_DECREF(self->optimizer);
+    PyObject_Free(self);
+}
+
+static PyTypeObject CounterExecutor_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    .tp_name = "counting_executor",
+    .tp_basicsize = sizeof(_PyCounterExecutorObject),
+    .tp_itemsize = 0,
+    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
+    .tp_dealloc = (destructor)counter_dealloc,
+};
+
+static _PyInterpreterFrame *
+counter_execute(_PyExecutorObject *self, _PyInterpreterFrame *frame, PyObject **stack_pointer)
+{
+    ((_PyCounterExecutorObject *)self)->optimizer->count++;
+    _PyFrame_SetStackPointer(frame, stack_pointer);
+    frame->prev_instr = ((_PyCounterExecutorObject *)self)->next_instr - 1;
+    Py_DECREF(self);
+    return frame;
+}
+
+static _PyExecutorObject *
+counter_optimize(
+    _PyOptimizerObject* self,
+    PyCodeObject *code,
+    _Py_CODEUNIT *instr)
+{
+    _PyCounterExecutorObject *executor = (_PyCounterExecutorObject *)_PyObject_New(&CounterExecutor_Type);
+    if (executor == NULL) {
+        return NULL;
+    }
+    executor->executor.execute = counter_execute;
+    Py_INCREF(self);
+    executor->optimizer = (_PyCounterOptimizerObject *)self;
+    executor->next_instr = instr;
+    return (_PyExecutorObject *)executor;
+}
+
+static PyObject *
+counter_get_counter(PyObject *self, PyObject *args)
+{
+    return PyLong_FromLongLong(((_PyCounterOptimizerObject *)self)->count);
+}
+
+static PyMethodDef counter_methods[] = {
+    { "get_count", counter_get_counter, METH_NOARGS, NULL },
+    { NULL, NULL },
+};
+
+static PyTypeObject CounterOptimizer_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    .tp_name = "Counter optimizer",
+    .tp_basicsize = sizeof(_PyCounterOptimizerObject),
+    .tp_itemsize = 0,
+    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
+    .tp_methods = counter_methods,
+};
+
+PyObject *
+PyUnstable_Optimizer_NewCounter(void)
+{
+    _PyCounterOptimizerObject *opt = (_PyCounterOptimizerObject *)_PyObject_New(&CounterOptimizer_Type);
+    if (opt == NULL) {
+        return NULL;
+    }
+    opt->base.optimize = counter_optimize;
+    opt->base.resume_threshold = UINT16_MAX;
+    opt->base.backedge_threshold = 0;
+    opt->count = 0;
+    return (PyObject *)opt;
+}
diff --git a/Python/pystate.c b/Python/pystate.c
index 39fe5473ed46b3..5b7a6c86ade4d7 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -695,6 +695,9 @@ init_interpreter(PyInterpreterState *interp,
     }
     interp->sys_profile_initialized = false;
     interp->sys_trace_initialized = false;
+    interp->optimizer = &_PyOptimizer_Default;
+    interp->optimizer_backedge_threshold = _PyOptimizer_Default.backedge_threshold;
+    interp->optimizer_resume_threshold = _PyOptimizer_Default.backedge_threshold;
     if (interp != &runtime->_main_interpreter) {
         /* Fix the self-referential, statically initialized fields. */
         interp->dtoa = (struct _dtoa_state)_dtoa_state_INIT(interp);
@@ -829,6 +832,11 @@ interpreter_clear(PyInterpreterState *interp, PyThreadState *tstate)
         tstate->_status.cleared = 0;
     }
 
+    Py_CLEAR(interp->optimizer);
+    interp->optimizer = &_PyOptimizer_Default;
+    interp->optimizer_backedge_threshold = _PyOptimizer_Default.backedge_threshold;
+    interp->optimizer_resume_threshold = _PyOptimizer_Default.backedge_threshold;
+
     /* It is possible that any of the objects below have a finalizer
        that runs Python code or otherwise relies on a thread state
        or even the interpreter state.  For now we trust that isn't
diff --git a/Tools/c-analyzer/cpython/ignored.tsv b/Tools/c-analyzer/cpython/ignored.tsv
index 45f895dea02a44..607976f5afdc68 100644
--- a/Tools/c-analyzer/cpython/ignored.tsv
+++ b/Tools/c-analyzer/cpython/ignored.tsv
@@ -356,6 +356,10 @@ Python/sysmodule.c	-	perf_map_state	-
 Python/sysmodule.c	-	_PySys_ImplCacheTag	-
 Python/sysmodule.c	-	_PySys_ImplName	-
 Python/sysmodule.c	-	whatstrings	-
+Python/optimizer.c	-	DefaultOptimizer_Type	-
+Python/optimizer.c	-	CounterExecutor_Type	-
+Python/optimizer.c	-	CounterOptimizer_Type	-
+Python/optimizer.c	-	_PyOptimizer_Default	-
 
 ##-----------------------
 ## test code