GH-125837: Split LOAD_CONST into three. (GH-125972)

* Add LOAD_CONST_IMMORTAL opcode

* Add LOAD_SMALL_INT opcode

* Remove RETURN_CONST opcode

Author: markshannon

Diff for: Doc/library/dis.rst

@@ -862,13 +862,6 @@ iterations of the loop.
    Returns with ``STACK[-1]`` to the caller of the function.
 
 
-.. opcode:: RETURN_CONST (consti)
-
-   Returns with ``co_consts[consti]`` to the caller of the function.
-
-   .. versionadded:: 3.12
-
-
 .. opcode:: YIELD_VALUE
 
    Yields ``STACK.pop()`` from a :term:`generator`.
@@ -1086,6 +1079,22 @@ iterations of the loop.
    Pushes ``co_consts[consti]`` onto the stack.
 
 
+.. opcode:: LOAD_SMALL_INT (i)
+
+   Pushes the integer ``i`` onto the stack.
+   ``i`` must be in ``range(256)``
+
+   .. versionadded:: 3.14
+
+
+.. opcode:: LOAD_CONST_IMMORTAL (consti)
+
+   Pushes ``co_consts[consti]`` onto the stack.
+   Can be used when the constant value is known to be immortal.
+
+   .. versionadded:: 3.14
+
+
 .. opcode:: LOAD_NAME (namei)
 
    Pushes the value associated with ``co_names[namei]`` onto the stack.

Diff for: Doc/whatsnew/3.12.rst

@@ -1123,7 +1123,7 @@ CPython bytecode changes
 * Add the :opcode:`LOAD_SUPER_ATTR` instruction. (Contributed by Carl Meyer and
   Vladimir Matveev in :gh:`103497`.)
 
-* Add the :opcode:`RETURN_CONST` instruction. (Contributed by Wenyang Wang in :gh:`101632`.)
+* Add the ``RETURN_CONST`` instruction. (Contributed by Wenyang Wang in :gh:`101632`.)
 
 Demos and Tools
 ===============

Diff for: Include/internal/pycore_magic_number.h

@@ -261,6 +261,7 @@ Known values:
     Python 3.14a1 3606 (Specialize CALL_KW)
     Python 3.14a1 3607 (Add pseudo instructions JUMP_IF_TRUE/FALSE)
     Python 3.14a1 3608 (Add support for slices)
+    Python 3.14a2 3609 (Add LOAD_SMALL_INT and LOAD_CONST_IMMORTAL instructions, remove RETURN_CONST)
 
     Python 3.15 will start with 3650
 
@@ -273,7 +274,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3608
+#define PYC_MAGIC_NUMBER 3609
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \

Diff for: Include/internal/pycore_opcode_metadata.h

@@ -47,7 +47,6 @@ extern "C" {
 
 #define IS_SCOPE_EXIT_OPCODE(opcode) \
         ((opcode) == RETURN_VALUE || \
-         (opcode) == RETURN_CONST || \
          (opcode) == RAISE_VARARGS || \
          (opcode) == RERAISE)