GH-113464: Add a JIT backend for tier 2 (GH-113465)

Add an option (--enable-experimental-jit for configure-based builds
or --experimental-jit for PCbuild-based ones) to build an
*experimental* just-in-time compiler, based on copy-and-patch (https://fredrikbk.com/publications/copy-and-patch.pdf).

See Tools/jit/README.md for more information on how to install the required build-time tooling.

1 files changed, 12 insertions, 0 deletions

diff --git a/Python/optimizer.c b/Python/optimizer.c
index db615068ff5..0d04b09fef1 100644
--- a/Python/optimizer.c
+++ b/Python/optimizer.c
@@ -7,6 +7,7 @@
 #include "pycore_optimizer.h"     // _Py_uop_analyze_and_optimize()
 #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>
@@ -227,6 +228,9 @@ static PyMethodDef executor_methods[] = {
 static void
 uop_dealloc(_PyExecutorObject *self) {
     _Py_ExecutorClear(self);
+#ifdef _Py_JIT
+    _PyJIT_Free(self);
+#endif
     PyObject_Free(self);
 }
 
@@ -790,6 +794,14 @@ make_executor_from_uops(_PyUOpInstruction *buffer, _PyBloomFilter *dependencies)
         }
     }
 #endif
+#ifdef _Py_JIT
+    executor->jit_code = NULL;
+    executor->jit_size = 0;
+    if (_PyJIT_Compile(executor, executor->trace, Py_SIZE(executor))) {
+        Py_DECREF(executor);
+        return NULL;
+    }
+#endif
     return executor;
 }