gh--101799: implement PREP_RERAISE_STAR as an intrinsic function

Author: iritkatriel

Doc/library/dis.rst

@@ -768,16 +768,6 @@ iterations of the loop.
 
    .. versionadded:: 3.11
 
-.. opcode:: PREP_RERAISE_STAR
-
-   Combines the raised and reraised exceptions list from ``STACK[-1]``, into an
-   exception group to propagate from a try-except* block. Uses the original exception
-   group from ``STACK[-2]`` to reconstruct the structure of reraised exceptions. Pops
-   two items from the stack and pushes the exception to reraise or ``None``
-   if there isn't one.
-
-   .. versionadded:: 3.11
-
 .. opcode:: WITH_EXCEPT_START
 
     Calls the function in position 4 on the stack with arguments (type, val, tb)
@@ -1529,6 +1519,18 @@ iterations of the loop.
 
    .. versionadded:: 3.12
 
+.. opcode:: CALL_INTRINSIC_2
+
+   Calls an intrinsic function with two arguments. Passes ``STACK[-2]``, ``STACK[-1]`` as the
+   arguments and sets ``STACK[-1]`` to the result. Used to implement functionality that is necessary but not performance critical.
+
+    The operand determines which intrinsic function is called:
+
+    * ``0`` Not valid
+    * ``1`` Calculates the :exc:`ExceptionGroup` to raise from a ``try-except*``.
+
+   .. versionadded:: 3.12
+
 
 **Pseudo-instructions**
 

Include/internal/pycore_intrinsics.h

@@ -1,4 +1,6 @@
 
+/* Unary Functions: */
+
 #define INTRINSIC_PRINT 1
 #define INTRINSIC_IMPORT_STAR 2
 #define INTRINSIC_STOPITERATION_ERROR 3
@@ -8,6 +10,17 @@
 
 #define MAX_INTRINSIC_1 6
 
+
+/* Binary Functions: */
+
+#define INTRINSIC_PREP_RERAISE_STAR 1
+
+#define MAX_INTRINSIC_2 1
+
+
 typedef PyObject *(*instrinsic_func1)(PyThreadState* tstate, PyObject *value);
+typedef PyObject *(*instrinsic_func2)(PyThreadState* tstate, PyObject *value1, PyObject *value2);
 
 extern instrinsic_func1 _PyIntrinsics_UnaryFunctions[];
+extern instrinsic_func2 _PyIntrinsics_BinaryFunctions[];
+

Include/internal/pycore_opcode.h

@@ -432,6 +432,7 @@ def _write_atomic(path, data, mode=0o666):
 #     Python 3.12a5 3516 (Add COMPARE_AND_BRANCH instruction)
 #     Python 3.12a5 3517 (Change YIELD_VALUE oparg to exception block depth)
 #     Python 3.12a5 3518 (Add RETURN_CONST instruction)
+#     Python 3.12a5 3519 (Remove PREP_RERAISE_STAR, add CALL_INTRINSIC2)
 
 #     Python 3.13 will start with 3550
 
@@ -444,7 +445,7 @@ 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 = (3518).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3519).to_bytes(2, 'little') + b'\r\n'
 
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 

Include/opcode.h

@@ -127,7 +127,6 @@ def pseudo_op(name, op, real_ops):
 
 def_op('SETUP_ANNOTATIONS', 85)
 
-def_op('PREP_RERAISE_STAR', 88)
 def_op('POP_EXCEPT', 89)
 
 HAVE_ARGUMENT = 90             # real opcodes from here have an argument:
@@ -224,6 +223,7 @@ def pseudo_op(name, op, real_ops):
 def_op('KW_NAMES', 172)
 hasconst.append(172)
 def_op('CALL_INTRINSIC_1', 173)
+def_op('CALL_INTRINSIC_2', 174)
 
 hasarg.extend([op for op in opmap.values() if op >= HAVE_ARGUMENT])
 

Lib/importlib/_bootstrap_external.py

@@ -501,7 +501,14 @@ dummy_func(
         inst(CALL_INTRINSIC_1, (value -- res)) {
             assert(oparg <= MAX_INTRINSIC_1);
             res = _PyIntrinsics_UnaryFunctions[oparg](tstate, value);
-            Py_DECREF(value);
+            DECREF_INPUTS();
+            ERROR_IF(res == NULL, error);
+        }
+
+        inst(CALL_INTRINSIC_2, (value2, value1 -- res)) {
+            assert(oparg <= MAX_INTRINSIC_2);
+            res = _PyIntrinsics_BinaryFunctions[oparg](tstate, value2, value1);
+            DECREF_INPUTS();
             ERROR_IF(res == NULL, error);
         }
 
@@ -773,15 +780,6 @@ dummy_func(
             goto exception_unwind;
         }
 
-        inst(PREP_RERAISE_STAR, (orig, excs -- val)) {
-            assert(PyList_Check(excs));
-
-            val = _PyExc_PrepReraiseStar(orig, excs);
-            DECREF_INPUTS();
-
-            ERROR_IF(val == NULL, error);
-        }
-
         inst(END_ASYNC_FOR, (awaitable, exc -- )) {
             assert(exc && PyExceptionInstance_Check(exc));
             if (PyErr_GivenExceptionMatches(exc, PyExc_StopAsyncIteration)) {
@@ -2367,7 +2365,7 @@ dummy_func(
         }
 
         // Cache layout: counter/1, func_version/2, min_args/1
-        // Neither CALL_INTRINSIC_1 nor CALL_FUNCTION_EX are members!
+        // Neither CALL_INTRINSIC_1/2 nor CALL_FUNCTION_EX are members!
         family(call, INLINE_CACHE_ENTRIES_CALL) = {
             CALL,
             CALL_BOUND_METHOD_EXACT_ARGS,

Lib/opcode.py

@@ -3429,7 +3429,7 @@ compiler_try_except(struct compiler *c, stmt_ty s)
 
    [orig, res, rest]                Ln+1:     LIST_APPEND 1  ) add unhandled exc to res (could be None)
 
-   [orig, res]                                PREP_RERAISE_STAR
+   [orig, res]                                CALL_INTRINSIC_2 PREP_RERAISE_STAR
    [exc]                                      COPY 1
    [exc, exc]                                 POP_JUMP_IF_NOT_NONE  RER
    [exc]                                      POP_TOP
@@ -3578,7 +3578,7 @@ compiler_try_star_except(struct compiler *c, stmt_ty s)
     NEW_JUMP_TARGET_LABEL(c, reraise);
 
     USE_LABEL(c, reraise_star);
-    ADDOP(c, NO_LOCATION, PREP_RERAISE_STAR);
+    ADDOP_I(c, NO_LOCATION, CALL_INTRINSIC_2, INTRINSIC_PREP_RERAISE_STAR);
     ADDOP_I(c, NO_LOCATION, COPY, 1);
     ADDOP_JUMP(c, NO_LOCATION, POP_JUMP_IF_NOT_NONE, reraise);
 

Python/bytecodes.c

@@ -9,6 +9,7 @@
 #include "pycore_pyerrors.h"
 
 
+/******** Unary functions ********/
 
 static PyObject *
 no_intrinsic(PyThreadState* tstate, PyObject *unused)
@@ -208,3 +209,20 @@ _PyIntrinsics_UnaryFunctions[] = {
     [INTRINSIC_UNARY_POSITIVE] = unary_pos,
     [INTRINSIC_LIST_TO_TUPLE] = list_to_tuple,
 };
+
+
+/******** Binary functions ********/
+
+
+static PyObject *
+prep_reraise_star(PyThreadState* unused, PyObject *orig, PyObject *excs)
+{
+    assert(PyList_Check(excs));
+    return _PyExc_PrepReraiseStar(orig, excs);
+}
+
+instrinsic_func2
+_PyIntrinsics_BinaryFunctions[] = {
+    [INTRINSIC_PREP_RERAISE_STAR] = prep_reraise_star,
+};
+