gh-106581: Project through calls (#108067)

This finishes the work begun in gh-107760. When, while projecting a superblock, we encounter a call to a short, simple function, the superblock will now enter the function using `_PUSH_FRAME`, continue through it, and leave it using `_POP_FRAME`, and then continue through the original code. Multiple frame pushes and pops are even possible. It is also possible to stop appending to the superblock in the middle of a called function, when running out of space or encountering an unsupported bytecode.

1 files changed, 9 insertions, 0 deletions

diff --git a/Include/internal/pycore_function.h b/Include/internal/pycore_function.h
index e844d32..3f3da8a 100644
--- a/Include/internal/pycore_function.h
+++ b/Include/internal/pycore_function.h
@@ -16,13 +16,22 @@ extern PyObject* _PyFunction_Vectorcall(
 
 #define FUNC_MAX_WATCHERS 8
 
+#define FUNC_VERSION_CACHE_SIZE (1<<12)  /* Must be a power of 2 */
 struct _py_func_state {
     uint32_t next_version;
+    // Borrowed references to function objects whose
+    // func_version % FUNC_VERSION_CACHE_SIZE
+    // once was equal to the index in the table.
+    // They are cleared when the function is deallocated.
+    PyFunctionObject *func_version_cache[FUNC_VERSION_CACHE_SIZE];
 };
 
 extern PyFunctionObject* _PyFunction_FromConstructor(PyFrameConstructor *constr);
 
 extern uint32_t _PyFunction_GetVersionForCurrentState(PyFunctionObject *func);
+extern void _PyFunction_SetVersion(PyFunctionObject *func, uint32_t version);
+PyFunctionObject *_PyFunction_LookupByVersion(uint32_t version);
+
 extern PyObject *_Py_set_function_type_params(
     PyThreadState* unused, PyObject *func, PyObject *type_params);