Optimization: Avoid taking reference for trivial constant returns

* We need to take a more full decision of what's immortal for best results

nuitka/Constants.py

@@ -335,6 +335,19 @@ def isCompileTimeConstantValue(value):
         return False
 
 
+if python_version < 0x3C0:
+
+    def isConstantImmortal(value):
+        # Not happening before 3.12, pylint: disable=unused-argument
+        return False
+
+else:
+
+    def isConstantImmortal(value):
+        # TODO: Add way more than these few ones.
+        return value in (True, False, None)
+
+
 # Shared empty values, it would cost time to create them locally.
 the_empty_dict = {}
 the_empty_list = []

nuitka/code_generation/ReturnCodes.py

@@ -9,6 +9,7 @@ by a try statement is accessible this way.
 
 """
 
+from nuitka.Constants import isConstantImmortal
 from nuitka.PythonVersions import python_version
 
 from .CodeHelpers import generateExpressionCode
@@ -59,9 +60,11 @@ def generateReturnConstantCode(statement, emit, context):
         emit("CHECK_OBJECT(%s);" % return_value_name)
         emit("Py_DECREF(%s);" % return_value_name)
 
+    constant = statement.getConstant()
+
     return_value_name.getCType().emitAssignmentCodeFromConstant(
         to_name=return_value_name,
-        constant=statement.getConstant(),
+        constant=constant,
         may_escape=True,
         emit=emit,
         context=context,
@@ -70,7 +73,10 @@ def generateReturnConstantCode(statement, emit, context):
     if context.needsCleanup(return_value_name):
         context.removeCleanupTempName(return_value_name)
     else:
-        emit("Py_INCREF(%s);" % return_value_name)
+        if isConstantImmortal(constant):
+            emit("Py_INCREF_IMMORTAL(%s);" % return_value_name)
+        else:
+            emit("Py_INCREF(%s);" % return_value_name)
 
     getGotoCode(label=context.getReturnTarget(), emit=emit)