gh-119180: Add LOAD_COMMON_CONSTANT opcode (#119321)

The PEP 649 implementation will require a way to load NotImplementedError
from the bytecode. @markshannon suggested implementing this by converting
LOAD_ASSERTION_ERROR into a more general mechanism for loading constants.

This PR adds this new opcode. I will work on the rest of the implementation
of the PEP separately.

Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
index 347a1e6..a3d7af2 100644
--- a/Python/executor_cases.c.h
+++ b/Python/executor_cases.c.h
@@ -1162,9 +1162,20 @@
             break;
         }
 
-        case _LOAD_ASSERTION_ERROR: {
+        case _LOAD_COMMON_CONSTANT: {
             PyObject *value;
-            value = Py_NewRef(PyExc_AssertionError);
+            oparg = CURRENT_OPARG();
+            // Keep in sync with _common_constants in opcode.py
+            switch(oparg) {
+                case CONSTANT_ASSERTIONERROR:
+                value = PyExc_AssertionError;
+                break;
+                case CONSTANT_NOTIMPLEMENTEDERROR:
+                value = PyExc_NotImplementedError;
+                break;
+                default:
+                Py_FatalError("bad LOAD_COMMON_CONSTANT oparg");
+            }
             stack_pointer[0] = value;
             stack_pointer += 1;
             break;