GH-112354: Initial implementation of warm up on exits and trace-stitching

Include/cpython/optimizer.h

@@ -36,12 +36,29 @@ typedef struct {
     uint64_t operand;  // A cache entry
 } _PyUOpInstruction;
 
+typedef struct _exit_data {
+    uint32_t target;
+    int16_t temperature;
+    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 */
-    _PyUOpInstruction trace[1];
+    uint32_t exit_count;
+    uint32_t code_size;
+    _PyExitData exits[1];
 } _PyExecutorObject;
 
+typedef struct _cold_exit {
+    _PyExecutorObject base;
+    _PyUOpInstruction uop;
+} _PyColdExitObject;
+
+
+extern _PyColdExitObject Py_FatalErrorExecutor;
+
 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. */
@@ -72,7 +89,7 @@ PyAPI_FUNC(_PyOptimizerObject *) PyUnstable_GetOptimizer(void);
 PyAPI_FUNC(_PyExecutorObject *) PyUnstable_GetExecutor(PyCodeObject *code, int offset);
 
 int
-_PyOptimizer_Optimize(struct _PyInterpreterFrame *frame, _Py_CODEUNIT *start, PyObject **stack_pointer);
+_PyOptimizer_Optimize(struct _PyInterpreterFrame *frame, _Py_CODEUNIT *start, PyObject **stack_pointer, _PyExecutorObject **exec_ptr);
 
 extern _PyOptimizerObject _PyOptimizer_Default;