[3.13] gh-120642: Move private PyCode APIs to the internal C API (#120643) (#121043)

gh-120642: Move private PyCode APIs to the internal C API (#120643)

* Move _Py_CODEUNIT and related functions to pycore_code.h.
* Move _Py_BackoffCounter to pycore_backoff.h.
* Move Include/cpython/optimizer.h content to pycore_optimizer.h.
* Remove Include/cpython/optimizer.h.
* Remove PyUnstable_Replace_Executor().

Rename functions:

* PyUnstable_GetExecutor() => _Py_GetExecutor()
* PyUnstable_GetOptimizer() => _Py_GetOptimizer()
* PyUnstable_SetOptimizer() => _Py_SetTier2Optimizer()
* PyUnstable_Optimizer_NewCounter() => _PyOptimizer_NewCounter()
* PyUnstable_Optimizer_NewUOpOptimizer() => _PyOptimizer_NewUOpOptimizer()

(cherry picked from commit 9e4a81f00fef689c6e18a64245aa064eaadc7ac7)

18 files changed, 238 insertions, 255 deletions

diff --git a/Include/Python.h b/Include/Python.h
index 95bc631..882b96b 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -131,6 +131,5 @@
 #include "fileutils.h"
 #include "cpython/pyfpe.h"
 #include "cpython/tracemalloc.h"
-#include "cpython/optimizer.h"
 
 #endif /* !Py_PYTHON_H */
diff --git a/Include/cpython/code.h b/Include/cpython/code.h
index ef8f930..07ed520 100644
--- a/Include/cpython/code.h
+++ b/Include/cpython/code.h
@@ -24,58 +24,6 @@ typedef struct _Py_GlobalMonitors {
     uint8_t tools[_PY_MONITORING_UNGROUPED_EVENTS];
 } _Py_GlobalMonitors;
 
-typedef struct {
-    union {
-        struct {
-            uint16_t backoff : 4;
-            uint16_t value : 12;
-        };
-        uint16_t as_counter;  // For printf("%#x", ...)
-    };
-} _Py_BackoffCounter;
-
-/* Each instruction in a code object is a fixed-width value,
- * currently 2 bytes: 1-byte opcode + 1-byte oparg.  The EXTENDED_ARG
- * opcode allows for larger values but the current limit is 3 uses
- * of EXTENDED_ARG (see Python/compile.c), for a maximum
- * 32-bit value.  This aligns with the note in Python/compile.c
- * (compiler_addop_i_line) indicating that the max oparg value is
- * 2**32 - 1, rather than INT_MAX.
- */
-
-typedef union {
-    uint16_t cache;
-    struct {
-        uint8_t code;
-        uint8_t arg;
-    } op;
-    _Py_BackoffCounter counter;  // First cache entry of specializable op
-} _Py_CODEUNIT;
-
-
-/* These macros only remain defined for compatibility. */
-#define _Py_OPCODE(word) ((word).op.code)
-#define _Py_OPARG(word) ((word).op.arg)
-
-static inline _Py_CODEUNIT
-_py_make_codeunit(uint8_t opcode, uint8_t oparg)
-{
-    // No designated initialisers because of C++ compat
-    _Py_CODEUNIT word;
-    word.op.code = opcode;
-    word.op.arg = oparg;
-    return word;
-}
-
-static inline void
-_py_set_opcode(_Py_CODEUNIT *word, uint8_t opcode)
-{
-    word->op.code = opcode;
-}
-
-#define _Py_MAKE_CODEUNIT(opcode, oparg) _py_make_codeunit((opcode), (oparg))
-#define _Py_SET_OPCODE(word, opcode) _py_set_opcode(&(word), (opcode))
-
 
 typedef struct {
     PyObject *_co_code;
diff --git a/Include/cpython/optimizer.h b/Include/cpython/optimizer.h
deleted file mode 100644
index 5f218d7..0000000
--- a/Include/cpython/optimizer.h
+++ /dev/null
@@ -1,164 +0,0 @@
-
-#ifndef Py_LIMITED_API
-#ifndef Py_OPTIMIZER_H
-#define Py_OPTIMIZER_H
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-typedef struct _PyExecutorLinkListNode {
-    struct _PyExecutorObject *next;
-    struct _PyExecutorObject *previous;
-} _PyExecutorLinkListNode;
-
-
-/* Bloom filter with m = 256
- * https://en.wikipedia.org/wiki/Bloom_filter */
-#define BLOOM_FILTER_WORDS 8
-
-typedef struct _bloom_filter {
-    uint32_t bits[BLOOM_FILTER_WORDS];
-} _PyBloomFilter;
-
-typedef struct {
-    uint8_t opcode;
-    uint8_t oparg;
-    uint8_t valid;
-    uint8_t linked;
-    int index;           // Index of ENTER_EXECUTOR (if code isn't NULL, below).
-    _PyBloomFilter bloom;
-    _PyExecutorLinkListNode links;
-    PyCodeObject *code;  // Weak (NULL if no corresponding ENTER_EXECUTOR).
-} _PyVMData;
-
-#define UOP_FORMAT_TARGET 0
-#define UOP_FORMAT_EXIT 1
-#define UOP_FORMAT_JUMP 2
-#define UOP_FORMAT_UNUSED 3
-
-/* Depending on the format,
- * the 32 bits between the oparg and operand are:
- * UOP_FORMAT_TARGET:
- *    uint32_t target;
- * UOP_FORMAT_EXIT
- *    uint16_t exit_index;
- *    uint16_t error_target;
- * UOP_FORMAT_JUMP
- *    uint16_t jump_target;
- *    uint16_t error_target;
- */
-typedef struct {
-    uint16_t opcode:14;
-    uint16_t format:2;
-    uint16_t oparg;
-    union {
-        uint32_t target;
-        struct {
-            union {
-                uint16_t exit_index;
-                uint16_t jump_target;
-            };
-            uint16_t error_target;
-        };
-    };
-    uint64_t operand;  // A cache entry
-} _PyUOpInstruction;
-
-static inline uint32_t uop_get_target(const _PyUOpInstruction *inst)
-{
-    assert(inst->format == UOP_FORMAT_TARGET);
-    return inst->target;
-}
-
-static inline uint16_t uop_get_exit_index(const _PyUOpInstruction *inst)
-{
-    assert(inst->format == UOP_FORMAT_EXIT);
-    return inst->exit_index;
-}
-
-static inline uint16_t uop_get_jump_target(const _PyUOpInstruction *inst)
-{
-    assert(inst->format == UOP_FORMAT_JUMP);
-    return inst->jump_target;
-}
-
-static inline uint16_t uop_get_error_target(const _PyUOpInstruction *inst)
-{
-    assert(inst->format != UOP_FORMAT_TARGET);
-    return inst->error_target;
-}
-
-typedef struct _exit_data {
-    uint32_t target;
-    _Py_BackoffCounter temperature;
-    const struct _PyExecutorObject *executor;
-} _PyExitData;
-
-typedef struct _PyExecutorObject {
-    PyObject_VAR_HEAD
-    const _PyUOpInstruction *trace;
-    _PyVMData vm_data; /* Used by the VM, but opaque to the optimizer */
-    uint32_t exit_count;
-    uint32_t code_size;
-    size_t jit_size;
-    void *jit_code;
-    void *jit_side_entry;
-    _PyExitData exits[1];
-} _PyExecutorObject;
-
-typedef struct _PyOptimizerObject _PyOptimizerObject;
-
-/* Should return > 0 if a new executor is created. O if no executor is produced and < 0 if an error occurred. */
-typedef int (*optimize_func)(
-    _PyOptimizerObject* self, struct _PyInterpreterFrame *frame,
-    _Py_CODEUNIT *instr, _PyExecutorObject **exec_ptr,
-    int curr_stackentries);
-
-struct _PyOptimizerObject {
-    PyObject_HEAD
-    optimize_func optimize;
-    /* Data needed by the optimizer goes here, but is opaque to the VM */
-};
-
-/** Test support **/
-typedef struct {
-    _PyOptimizerObject base;
-    int64_t count;
-} _PyCounterOptimizerObject;
-
-PyAPI_FUNC(int) PyUnstable_Replace_Executor(PyCodeObject *code, _Py_CODEUNIT *instr, _PyExecutorObject *executor);
-
-_PyOptimizerObject *_Py_SetOptimizer(PyInterpreterState *interp, _PyOptimizerObject* optimizer);
-
-PyAPI_FUNC(int) PyUnstable_SetOptimizer(_PyOptimizerObject* optimizer);
-
-PyAPI_FUNC(_PyOptimizerObject *) PyUnstable_GetOptimizer(void);
-
-PyAPI_FUNC(_PyExecutorObject *) PyUnstable_GetExecutor(PyCodeObject *code, int offset);
-
-void _Py_ExecutorInit(_PyExecutorObject *, const _PyBloomFilter *);
-void _Py_ExecutorDetach(_PyExecutorObject *);
-void _Py_BloomFilter_Init(_PyBloomFilter *);
-void _Py_BloomFilter_Add(_PyBloomFilter *bloom, void *obj);
-PyAPI_FUNC(void) _Py_Executor_DependsOn(_PyExecutorObject *executor, void *obj);
-/* For testing */
-PyAPI_FUNC(PyObject *)PyUnstable_Optimizer_NewCounter(void);
-PyAPI_FUNC(PyObject *)PyUnstable_Optimizer_NewUOpOptimizer(void);
-
-#define _Py_MAX_ALLOWED_BUILTINS_MODIFICATIONS 3
-#define _Py_MAX_ALLOWED_GLOBALS_MODIFICATIONS 6
-
-#ifdef _Py_TIER2
-PyAPI_FUNC(void) _Py_Executors_InvalidateDependency(PyInterpreterState *interp, void *obj, int is_invalidation);
-PyAPI_FUNC(void) _Py_Executors_InvalidateAll(PyInterpreterState *interp, int is_invalidation);
-#else
-#  define _Py_Executors_InvalidateDependency(A, B, C) ((void)0)
-#  define _Py_Executors_InvalidateAll(A, B) ((void)0)
-#endif
-
-
-#ifdef __cplusplus
-}
-#endif
-#endif /* !Py_OPTIMIZER_H */
-#endif /* Py_LIMITED_API */
diff --git a/Include/internal/pycore_backoff.h b/Include/internal/pycore_backoff.h
index 90735b2..0bcca1e 100644
--- a/Include/internal/pycore_backoff.h
+++ b/Include/internal/pycore_backoff.h
@@ -13,6 +13,18 @@ extern "C" {
 #include <stdbool.h>
 #include <stdint.h>
 
+
+typedef struct {
+    union {
+        struct {
+            uint16_t backoff : 4;
+            uint16_t value : 12;
+        };
+        uint16_t as_counter;  // For printf("%#x", ...)
+    };
+} _Py_BackoffCounter;
+
+
 /* 16-bit countdown counters using exponential backoff.
 
    These are used by the adaptive specializer to count down until
diff --git a/Include/internal/pycore_code.h b/Include/internal/pycore_code.h
index bcbaf60..48ff270 100644
--- a/Include/internal/pycore_code.h
+++ b/Include/internal/pycore_code.h
@@ -9,6 +9,50 @@ extern "C" {
 #endif
 
 #include "pycore_lock.h"        // PyMutex
+#include "pycore_backoff.h"     // _Py_BackoffCounter
+
+
+/* Each instruction in a code object is a fixed-width value,
+ * currently 2 bytes: 1-byte opcode + 1-byte oparg.  The EXTENDED_ARG
+ * opcode allows for larger values but the current limit is 3 uses
+ * of EXTENDED_ARG (see Python/compile.c), for a maximum
+ * 32-bit value.  This aligns with the note in Python/compile.c
+ * (compiler_addop_i_line) indicating that the max oparg value is
+ * 2**32 - 1, rather than INT_MAX.
+ */
+
+typedef union {
+    uint16_t cache;
+    struct {
+        uint8_t code;
+        uint8_t arg;
+    } op;
+    _Py_BackoffCounter counter;  // First cache entry of specializable op
+} _Py_CODEUNIT;
+
+
+/* These macros only remain defined for compatibility. */
+#define _Py_OPCODE(word) ((word).op.code)
+#define _Py_OPARG(word) ((word).op.arg)
+
+static inline _Py_CODEUNIT
+_py_make_codeunit(uint8_t opcode, uint8_t oparg)
+{
+    // No designated initialisers because of C++ compat
+    _Py_CODEUNIT word;
+    word.op.code = opcode;
+    word.op.arg = oparg;
+    return word;
+}
+
+static inline void
+_py_set_opcode(_Py_CODEUNIT *word, uint8_t opcode)
+{
+    word->op.code = opcode;
+}
+
+#define _Py_MAKE_CODEUNIT(opcode, oparg) _py_make_codeunit((opcode), (oparg))
+#define _Py_SET_OPCODE(word, opcode) _py_set_opcode(&(word), (opcode))
 
 
 // We hide some of the newer PyCodeObject fields behind macros.
diff --git a/Include/internal/pycore_interp.h b/Include/internal/pycore_interp.h
index 6b5f50b..45d85b2 100644
--- a/Include/internal/pycore_interp.h
+++ b/Include/internal/pycore_interp.h
@@ -30,6 +30,7 @@ extern "C" {
 #include "pycore_list.h"          // struct _Py_list_state
 #include "pycore_mimalloc.h"      // struct _mimalloc_interp_state
 #include "pycore_object_state.h"  // struct _py_object_state
+#include "pycore_optimizer.h"     // _PyOptimizerObject
 #include "pycore_obmalloc.h"      // struct _obmalloc_state
 #include "pycore_qsbr.h"          // struct _qsbr_state
 #include "pycore_tstate.h"        // _PyThreadStateImpl
diff --git a/Include/internal/pycore_optimizer.h b/Include/internal/pycore_optimizer.h
index c422e2f..49aa67c 100644
--- a/Include/internal/pycore_optimizer.h
+++ b/Include/internal/pycore_optimizer.h
@@ -11,12 +11,162 @@ extern "C" {
 #include "pycore_uop_ids.h"
 #include <stdbool.h>
 
+
+typedef struct _PyExecutorLinkListNode {
+    struct _PyExecutorObject *next;
+    struct _PyExecutorObject *previous;
+} _PyExecutorLinkListNode;
+
+
+/* Bloom filter with m = 256
+ * https://en.wikipedia.org/wiki/Bloom_filter */
+#define BLOOM_FILTER_WORDS 8
+
+typedef struct _bloom_filter {
+    uint32_t bits[BLOOM_FILTER_WORDS];
+} _PyBloomFilter;
+
+typedef struct {
+    uint8_t opcode;
+    uint8_t oparg;
+    uint8_t valid;
+    uint8_t linked;
+    int index;           // Index of ENTER_EXECUTOR (if code isn't NULL, below).
+    _PyBloomFilter bloom;
+    _PyExecutorLinkListNode links;
+    PyCodeObject *code;  // Weak (NULL if no corresponding ENTER_EXECUTOR).
+} _PyVMData;
+
+#define UOP_FORMAT_TARGET 0
+#define UOP_FORMAT_EXIT 1
+#define UOP_FORMAT_JUMP 2
+#define UOP_FORMAT_UNUSED 3
+
+/* Depending on the format,
+ * the 32 bits between the oparg and operand are:
+ * UOP_FORMAT_TARGET:
+ *    uint32_t target;
+ * UOP_FORMAT_EXIT
+ *    uint16_t exit_index;
+ *    uint16_t error_target;
+ * UOP_FORMAT_JUMP
+ *    uint16_t jump_target;
+ *    uint16_t error_target;
+ */
+typedef struct {
+    uint16_t opcode:14;
+    uint16_t format:2;
+    uint16_t oparg;
+    union {
+        uint32_t target;
+        struct {
+            union {
+                uint16_t exit_index;
+                uint16_t jump_target;
+            };
+            uint16_t error_target;
+        };
+    };
+    uint64_t operand;  // A cache entry
+} _PyUOpInstruction;
+
+static inline uint32_t uop_get_target(const _PyUOpInstruction *inst)
+{
+    assert(inst->format == UOP_FORMAT_TARGET);
+    return inst->target;
+}
+
+static inline uint16_t uop_get_exit_index(const _PyUOpInstruction *inst)
+{
+    assert(inst->format == UOP_FORMAT_EXIT);
+    return inst->exit_index;
+}
+
+static inline uint16_t uop_get_jump_target(const _PyUOpInstruction *inst)
+{
+    assert(inst->format == UOP_FORMAT_JUMP);
+    return inst->jump_target;
+}
+
+static inline uint16_t uop_get_error_target(const _PyUOpInstruction *inst)
+{
+    assert(inst->format != UOP_FORMAT_TARGET);
+    return inst->error_target;
+}
+
+typedef struct _exit_data {
+    uint32_t target;
+    _Py_BackoffCounter temperature;
+    const struct _PyExecutorObject *executor;
+} _PyExitData;
+
+typedef struct _PyExecutorObject {
+    PyObject_VAR_HEAD
+    const _PyUOpInstruction *trace;
+    _PyVMData vm_data; /* Used by the VM, but opaque to the optimizer */
+    uint32_t exit_count;
+    uint32_t code_size;
+    size_t jit_size;
+    void *jit_code;
+    void *jit_side_entry;
+    _PyExitData exits[1];
+} _PyExecutorObject;
+
+typedef struct _PyOptimizerObject _PyOptimizerObject;
+
+/* Should return > 0 if a new executor is created. O if no executor is produced and < 0 if an error occurred. */
+typedef int (*optimize_func)(
+    _PyOptimizerObject* self, struct _PyInterpreterFrame *frame,
+    _Py_CODEUNIT *instr, _PyExecutorObject **exec_ptr,
+    int curr_stackentries);
+
+struct _PyOptimizerObject {
+    PyObject_HEAD
+    optimize_func optimize;
+    /* Data needed by the optimizer goes here, but is opaque to the VM */
+};
+
+/** Test support **/
+typedef struct {
+    _PyOptimizerObject base;
+    int64_t count;
+} _PyCounterOptimizerObject;
+
+_PyOptimizerObject *_Py_SetOptimizer(PyInterpreterState *interp, _PyOptimizerObject* optimizer);
+
+PyAPI_FUNC(int) _Py_SetTier2Optimizer(_PyOptimizerObject* optimizer);
+
+PyAPI_FUNC(_PyOptimizerObject *) _Py_GetOptimizer(void);
+
+PyAPI_FUNC(_PyExecutorObject *) _Py_GetExecutor(PyCodeObject *code, int offset);
+
+void _Py_ExecutorInit(_PyExecutorObject *, const _PyBloomFilter *);
+void _Py_ExecutorDetach(_PyExecutorObject *);
+void _Py_BloomFilter_Init(_PyBloomFilter *);
+void _Py_BloomFilter_Add(_PyBloomFilter *bloom, void *obj);
+PyAPI_FUNC(void) _Py_Executor_DependsOn(_PyExecutorObject *executor, void *obj);
+/* For testing */
+PyAPI_FUNC(PyObject *) _PyOptimizer_NewCounter(void);
+PyAPI_FUNC(PyObject *) _PyOptimizer_NewUOpOptimizer(void);
+
+#define _Py_MAX_ALLOWED_BUILTINS_MODIFICATIONS 3
+#define _Py_MAX_ALLOWED_GLOBALS_MODIFICATIONS 6
+
+#ifdef _Py_TIER2
+PyAPI_FUNC(void) _Py_Executors_InvalidateDependency(PyInterpreterState *interp, void *obj, int is_invalidation);
+PyAPI_FUNC(void) _Py_Executors_InvalidateAll(PyInterpreterState *interp, int is_invalidation);
+#else
+#  define _Py_Executors_InvalidateDependency(A, B, C) ((void)0)
+#  define _Py_Executors_InvalidateAll(A, B) ((void)0)
+#endif
+
+
 // This is the length of the trace we project initially.
 #define UOP_MAX_TRACE_LENGTH 800
 
 #define TRACE_STACK_SIZE 5
 
-int _Py_uop_analyze_and_optimize(_PyInterpreterFrame *frame,
+int _Py_uop_analyze_and_optimize(struct _PyInterpreterFrame *frame,
     _PyUOpInstruction *trace, int trace_len, int curr_stackentries,
     _PyBloomFilter *dependencies);
 
@@ -114,7 +264,7 @@ extern int _Py_uop_frame_pop(_Py_UOpsContext *ctx);
 
 PyAPI_FUNC(PyObject *) _Py_uop_symbols_test(PyObject *self, PyObject *ignored);
 
-PyAPI_FUNC(int) _PyOptimizer_Optimize(_PyInterpreterFrame *frame, _Py_CODEUNIT *start, PyObject **stack_pointer, _PyExecutorObject **exec_ptr);
+PyAPI_FUNC(int) _PyOptimizer_Optimize(struct _PyInterpreterFrame *frame, _Py_CODEUNIT *start, PyObject **stack_pointer, _PyExecutorObject **exec_ptr);
 
 #ifdef __cplusplus
 }
diff --git a/Makefile.pre.in b/Makefile.pre.in
index 6a7b21f..22d8bb9 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -1103,7 +1103,6 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/cpython/object.h \
 		$(srcdir)/Include/cpython/objimpl.h \
 		$(srcdir)/Include/cpython/odictobject.h \
-		$(srcdir)/Include/cpython/optimizer.h \
 		$(srcdir)/Include/cpython/picklebufobject.h \
 		$(srcdir)/Include/cpython/pthread_stubs.h \
 		$(srcdir)/Include/cpython/pyatomic.h \
diff --git a/Misc/NEWS.d/next/C API/2024-06-19-21-27-42.gh-issue-120642.UlKClN.rst b/Misc/NEWS.d/next/C API/2024-06-19-21-27-42.gh-issue-120642.UlKClN.rst
new file mode 100644
index 0000000..a61224e
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2024-06-19-21-27-42.gh-issue-120642.UlKClN.rst
@@ -0,0 +1,10 @@
+Remove the following unstable functions:
+
+* ``PyUnstable_Replace_Executor()``
+* ``PyUnstable_SetOptimizer()``
+* ``PyUnstable_GetOptimizer()``
+* ``PyUnstable_GetExecutor()``
+* ``PyUnstable_Optimizer_NewCounter()``
+* ``PyUnstable_Optimizer_NewUOpOptimizer()``
+
+Patch by Victor Stinner.
diff --git a/Misc/NEWS.d/next/C API/2024-06-26-11-29-01.gh-issue-120642.H7P9qK.rst b/Misc/NEWS.d/next/C API/2024-06-26-11-29-01.gh-issue-120642.H7P9qK.rst
new file mode 100644
index 0000000..24fb6ca
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2024-06-26-11-29-01.gh-issue-120642.H7P9qK.rst
@@ -0,0 +1,3 @@
+Remove the private ``_Py_CODEUNIT`` type from the public C API. The internal
+``pycore_code.h`` header should now be used to get this internal type. Patch by
+Victor Stinner.
diff --git a/Modules/_opcode.c b/Modules/_opcode.c
index cc72cb1..4bf6393 100644
--- a/Modules/_opcode.c
+++ b/Modules/_opcode.c
@@ -5,9 +5,10 @@
 #include "Python.h"
 #include "compile.h"
 #include "opcode.h"
-#include "internal/pycore_code.h"
-#include "internal/pycore_compile.h"
-#include "internal/pycore_intrinsics.h"
+#include "pycore_code.h"
+#include "pycore_compile.h"
+#include "pycore_intrinsics.h"
+#include "pycore_optimizer.h"     // _Py_GetExecutor()
 
 /*[clinic input]
 module _opcode
@@ -368,7 +369,7 @@ _opcode_get_executor_impl(PyObject *module, PyObject *code, int offset)
         return NULL;
     }
 #ifdef _Py_TIER2
-    return (PyObject *)PyUnstable_GetExecutor((PyCodeObject *)code, offset);
+    return (PyObject *)_Py_GetExecutor((PyCodeObject *)code, offset);
 #else
     PyErr_Format(PyExc_RuntimeError,
                  "Executors are not available in this build");
diff --git a/Modules/_testinternalcapi.c b/Modules/_testinternalcapi.c
index 8c65b80..5055bca 100644
--- a/Modules/_testinternalcapi.c
+++ b/Modules/_testinternalcapi.c
@@ -990,13 +990,13 @@ get_co_framesize(PyObject *self, PyObject *arg)
 static PyObject *
 new_counter_optimizer(PyObject *self, PyObject *arg)
 {
-    return PyUnstable_Optimizer_NewCounter();
+    return _PyOptimizer_NewCounter();
 }
 
 static PyObject *
 new_uop_optimizer(PyObject *self, PyObject *arg)
 {
-    return PyUnstable_Optimizer_NewUOpOptimizer();
+    return _PyOptimizer_NewUOpOptimizer();
 }
 
 static PyObject *
@@ -1005,7 +1005,7 @@ set_optimizer(PyObject *self, PyObject *opt)
     if (opt == Py_None) {
         opt = NULL;
     }
-    if (PyUnstable_SetOptimizer((_PyOptimizerObject*)opt) < 0) {
+    if (_Py_SetTier2Optimizer((_PyOptimizerObject*)opt) < 0) {
         return NULL;
     }
     Py_RETURN_NONE;
@@ -1016,7 +1016,7 @@ get_optimizer(PyObject *self, PyObject *Py_UNUSED(ignored))
 {
     PyObject *opt = NULL;
 #ifdef _Py_TIER2
-    opt = (PyObject *)PyUnstable_GetOptimizer();
+    opt = (PyObject *)_Py_GetOptimizer();
 #endif
     if (opt == NULL) {
         Py_RETURN_NONE;
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index 6edcef7..33ab50f 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -166,7 +166,6 @@
     <ClInclude Include="..\Include\cpython\object.h" />
     <ClInclude Include="..\Include\cpython\objimpl.h" />
     <ClInclude Include="..\Include\cpython\odictobject.h" />
-    <ClInclude Include="..\Include\cpython\optimizer.h" />
     <ClInclude Include="..\Include\cpython\parser_interface.h" />
     <ClInclude Include="..\Include\cpython\picklebufobject.h" />
     <ClInclude Include="..\Include\cpython\pyarena.h" />
diff --git a/PCbuild/pythoncore.vcxproj.filters b/PCbuild/pythoncore.vcxproj.filters
index 824648e..828f14d 100644
--- a/PCbuild/pythoncore.vcxproj.filters
+++ b/PCbuild/pythoncore.vcxproj.filters
@@ -417,9 +417,6 @@
     <ClInclude Include="..\Include\cpython\odictobject.h">
       <Filter>Include</Filter>
     </ClInclude>
-    <ClInclude Include="..\Include\cpython\optimizer.h">
-      <Filter>Include</Filter>
-    </ClInclude>
     <ClInclude Include="..\Include\cpython\unicodeobject.h">
       <Filter>Include\cpython</Filter>
     </ClInclude>
diff --git a/Python/optimizer.c b/Python/optimizer.c
index 9dddc43..50ab71c 100644
--- a/Python/optimizer.c
+++ b/Python/optimizer.c
@@ -12,7 +12,6 @@
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
 #include "pycore_uop_ids.h"
 #include "pycore_jit.h"
-#include "cpython/optimizer.h"
 #include <stdbool.h>
 #include <stdint.h>
 #include <stddef.h>
@@ -105,18 +104,6 @@ insert_executor(PyCodeObject *code, _Py_CODEUNIT *instr, int index, _PyExecutorO
     instr->op.arg = index;
 }
 
-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 = instr->op.arg;
-    assert(index >= 0);
-    insert_executor(code, instr, index, new);
-    return 0;
-}
 
 static int
 never_optimize(
@@ -144,7 +131,7 @@ static _PyOptimizerObject _PyOptimizer_Default = {
 };
 
 _PyOptimizerObject *
-PyUnstable_GetOptimizer(void)
+_Py_GetOptimizer(void)
 {
     PyInterpreterState *interp = _PyInterpreterState_GET();
     if (interp->optimizer == &_PyOptimizer_Default) {
@@ -195,7 +182,7 @@ _Py_SetOptimizer(PyInterpreterState *interp, _PyOptimizerObject *optimizer)
 }
 
 int
-PyUnstable_SetOptimizer(_PyOptimizerObject *optimizer)
+_Py_SetTier2Optimizer(_PyOptimizerObject *optimizer)
 {
     PyInterpreterState *interp = _PyInterpreterState_GET();
     _PyOptimizerObject *old = _Py_SetOptimizer(interp, optimizer);
@@ -240,7 +227,7 @@ _PyOptimizer_Optimize(
 }
 
 _PyExecutorObject *
-PyUnstable_GetExecutor(PyCodeObject *code, int offset)
+_Py_GetExecutor(PyCodeObject *code, int offset)
 {
     int code_len = (int)Py_SIZE(code);
     for (int i = 0 ; i < code_len;) {
@@ -1349,7 +1336,7 @@ PyTypeObject _PyUOpOptimizer_Type = {
 };
 
 PyObject *
-PyUnstable_Optimizer_NewUOpOptimizer(void)
+_PyOptimizer_NewUOpOptimizer(void)
 {
     _PyOptimizerObject *opt = PyObject_New(_PyOptimizerObject, &_PyUOpOptimizer_Type);
     if (opt == NULL) {
@@ -1437,7 +1424,7 @@ PyTypeObject _PyCounterOptimizer_Type = {
 };
 
 PyObject *
-PyUnstable_Optimizer_NewCounter(void)
+_PyOptimizer_NewCounter(void)
 {
     _PyCounterOptimizerObject *opt = (_PyCounterOptimizerObject *)_PyObject_New(&_PyCounterOptimizer_Type);
     if (opt == NULL) {
diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 03148c2..4f1f404 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -21,7 +21,6 @@
 #include "pycore_uop_metadata.h"
 #include "pycore_dict.h"
 #include "pycore_long.h"
-#include "cpython/optimizer.h"
 #include "pycore_optimizer.h"
 #include "pycore_object.h"
 #include "pycore_dict.h"
diff --git a/Python/optimizer_symbols.c b/Python/optimizer_symbols.c
index e80d15b..8f855cd 100644
--- a/Python/optimizer_symbols.c
+++ b/Python/optimizer_symbols.c
@@ -2,7 +2,6 @@
 
 #include "Python.h"
 
-#include "cpython/optimizer.h"
 #include "pycore_code.h"
 #include "pycore_frame.h"
 #include "pycore_long.h"
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 3639cf6..e5f749b 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -32,7 +32,6 @@
 #include "pycore_typevarobject.h" // _Py_clear_generic_types()
 #include "pycore_unicodeobject.h" // _PyUnicode_InitTypes()
 #include "pycore_weakref.h"       // _PyWeakref_GET_REF()
-#include "cpython/optimizer.h"    // _Py_MAX_ALLOWED_BUILTINS_MODIFICATIONS
 #include "pycore_obmalloc.h"      // _PyMem_init_obmalloc()
 
 #include "opcode.h"
@@ -1299,11 +1298,11 @@ init_interp_main(PyThreadState *tstate)
             enabled = *env != '0';
         }
         if (enabled) {
-            PyObject *opt = PyUnstable_Optimizer_NewUOpOptimizer();
+            PyObject *opt = _PyOptimizer_NewUOpOptimizer();
             if (opt == NULL) {
                 return _PyStatus_ERR("can't initialize optimizer");
             }
-            if (PyUnstable_SetOptimizer((_PyOptimizerObject *)opt)) {
+            if (_Py_SetTier2Optimizer((_PyOptimizerObject *)opt)) {
                 return _PyStatus_ERR("can't install optimizer");
             }
             Py_DECREF(opt);