gh-126835: Move constant tuple folding to CFG

Lib/test/test_ast/test_ast.py

@@ -153,22 +153,6 @@ def test_optimization_levels__debug__(self):
                         self.assertIsInstance(res.body[0].value, ast.Name)
                         self.assertEqual(res.body[0].value.id, expected)
 
-    def test_optimization_levels_const_folding(self):
-        folded = ('Expr', (1, 0, 1, 6), ('Constant', (1, 0, 1, 6), (1, 2), None))
-        not_folded = ('Expr', (1, 0, 1, 6),
-                         ('Tuple', (1, 0, 1, 6),
-                             [('Constant', (1, 1, 1, 2), 1, None),
-                             ('Constant', (1, 4, 1, 5), 2, None)], ('Load',)))
-
-        cases = [(-1, not_folded), (0, not_folded), (1, folded), (2, folded)]
-        for (optval, expected) in cases:
-            with self.subTest(optval=optval):
-                tree1 = ast.parse("(1, 2)", optimize=optval)
-                tree2 = ast.parse(ast.parse("(1, 2)"), optimize=optval)
-                for tree in [tree1, tree2]:
-                    res = to_tuple(tree.body[0])
-                    self.assertEqual(res, expected)
-
     def test_invalid_position_information(self):
         invalid_linenos = [
             (10, 1), (-10, -11), (10, -11), (-5, -2), (-5, 1)
@@ -3193,101 +3177,6 @@ def test_folding_format(self):
 
         self.assert_ast(code, non_optimized_target, optimized_target)
 
-
-    def test_folding_tuple(self):
-        code = "(1,)"
-
-        non_optimized_target = self.wrap_expr(ast.Tuple(elts=[ast.Constant(1)]))
-        optimized_target = self.wrap_expr(ast.Constant(value=(1,)))
-
-        self.assert_ast(code, non_optimized_target, optimized_target)
-
-    def test_folding_type_param_in_function_def(self):
-        code = "def foo[%s = (1, 2)](): pass"
-
-        unoptimized_tuple = ast.Tuple(elts=[ast.Constant(1), ast.Constant(2)])
-        unoptimized_type_params = [
-            ("T", "T", ast.TypeVar),
-            ("**P", "P", ast.ParamSpec),
-            ("*Ts", "Ts", ast.TypeVarTuple),
-        ]
-
-        for type, name, type_param in unoptimized_type_params:
-            result_code = code % type
-            optimized_target = self.wrap_statement(
-                ast.FunctionDef(
-                    name='foo',
-                    args=ast.arguments(),
-                    body=[ast.Pass()],
-                    type_params=[type_param(name=name, default_value=ast.Constant((1, 2)))]
-                )
-            )
-            non_optimized_target = self.wrap_statement(
-                ast.FunctionDef(
-                    name='foo',
-                    args=ast.arguments(),
-                    body=[ast.Pass()],
-                    type_params=[type_param(name=name, default_value=unoptimized_tuple)]
-                )
-            )
-            self.assert_ast(result_code, non_optimized_target, optimized_target)
-
-    def test_folding_type_param_in_class_def(self):
-        code = "class foo[%s = (1, 2)]: pass"
-
-        unoptimized_tuple = ast.Tuple(elts=[ast.Constant(1), ast.Constant(2)])
-        unoptimized_type_params = [
-            ("T", "T", ast.TypeVar),
-            ("**P", "P", ast.ParamSpec),
-            ("*Ts", "Ts", ast.TypeVarTuple),
-        ]
-
-        for type, name, type_param in unoptimized_type_params:
-            result_code = code % type
-            optimized_target = self.wrap_statement(
-                ast.ClassDef(
-                    name='foo',
-                    body=[ast.Pass()],
-                    type_params=[type_param(name=name, default_value=ast.Constant((1, 2)))]
-                )
-            )
-            non_optimized_target = self.wrap_statement(
-                ast.ClassDef(
-                    name='foo',
-                    body=[ast.Pass()],
-                    type_params=[type_param(name=name, default_value=unoptimized_tuple)]
-                )
-            )
-            self.assert_ast(result_code, non_optimized_target, optimized_target)
-
-    def test_folding_type_param_in_type_alias(self):
-        code = "type foo[%s = (1, 2)] = 1"
-
-        unoptimized_tuple = ast.Tuple(elts=[ast.Constant(1), ast.Constant(2)])
-        unoptimized_type_params = [
-            ("T", "T", ast.TypeVar),
-            ("**P", "P", ast.ParamSpec),
-            ("*Ts", "Ts", ast.TypeVarTuple),
-        ]
-
-        for type, name, type_param in unoptimized_type_params:
-            result_code = code % type
-            optimized_target = self.wrap_statement(
-                ast.TypeAlias(
-                    name=ast.Name(id='foo', ctx=ast.Store()),
-                    type_params=[type_param(name=name, default_value=ast.Constant((1, 2)))],
-                    value=ast.Constant(value=1),
-                )
-            )
-            non_optimized_target = self.wrap_statement(
-                ast.TypeAlias(
-                    name=ast.Name(id='foo', ctx=ast.Store()),
-                    type_params=[type_param(name=name, default_value=unoptimized_tuple)],
-                    value=ast.Constant(value=1),
-                )
-            )
-            self.assert_ast(result_code, non_optimized_target, optimized_target)
-
     def test_folding_match_case_allowed_expressions(self):
         def get_match_case_values(node):
             result = []

Lib/test/test_builtin.py

@@ -554,7 +554,7 @@ def test_compile_async_generator(self):
         self.assertEqual(type(glob['ticker']()), AsyncGeneratorType)
 
     def test_compile_ast(self):
-        args = ("a*(1,2)", "f.py", "exec")
+        args = ("a*__debug__", "f.py", "exec")
         raw = compile(*args, flags = ast.PyCF_ONLY_AST).body[0]
         opt1 = compile(*args, flags = ast.PyCF_OPTIMIZED_AST).body[0]
         opt2 = compile(ast.parse(args[0]), *args[1:], flags = ast.PyCF_OPTIMIZED_AST).body[0]
@@ -565,14 +565,14 @@ def test_compile_ast(self):
             self.assertIsInstance(tree.value.left, ast.Name)
             self.assertEqual(tree.value.left.id, 'a')
 
-        raw_right = raw.value.right  # expect Tuple((1, 2))
-        self.assertIsInstance(raw_right, ast.Tuple)
-        self.assertListEqual([elt.value for elt in raw_right.elts], [1, 2])
+        raw_right = raw.value.right
+        self.assertIsInstance(raw_right, ast.Name)
+        self.assertEqual(raw_right.id, "__debug__")
 
         for opt in [opt1, opt2]:
-            opt_right = opt.value.right  # expect Constant((1,2))
+            opt_right = opt.value.right
             self.assertIsInstance(opt_right, ast.Constant)
-            self.assertEqual(opt_right.value, (1, 2))
+            self.assertEqual(opt_right.value, True)
 
     def test_delattr(self):
         sys.spam = 1

Lib/test/test_compile.py

@@ -793,9 +793,9 @@ def check_same_constant(const):
         f1, f2 = lambda: "not a name", lambda: ("not a name",)
         f3 = lambda x: x in {("not a name",)}
         self.assertIs(f1.__code__.co_consts[0],
-                      f2.__code__.co_consts[0][0])
+                      f2.__code__.co_consts[1][0])
         self.assertIs(next(iter(f3.__code__.co_consts[1])),
-                      f2.__code__.co_consts[0])
+                      f2.__code__.co_consts[1])
 
         # {0} is converted to a constant frozenset({0}) by the peephole
         # optimizer
@@ -1129,6 +1129,31 @@ def foo(x):
                 self.assertIn('LOAD_ATTR', instructions)
                 self.assertIn('CALL', instructions)
 
+    def test_folding_type_param(self):
+        get_code_fn_cls = lambda x: x.co_consts[0].co_consts[2]
+        get_code_type_alias = lambda x: x.co_consts[0].co_consts[3]
+        snippets = [
+            ("def foo[T = 40 + 5](): pass", get_code_fn_cls),
+            ("def foo[**P = 40 + 5](): pass", get_code_fn_cls),
+            ("def foo[*Ts = 40 + 5](): pass", get_code_fn_cls),
+            ("class foo[T = 40 + 5]: pass", get_code_fn_cls),
+            ("class foo[**P = 40 + 5]: pass", get_code_fn_cls),
+            ("class foo[*Ts = 40 + 5]: pass", get_code_fn_cls),
+            ("type foo[T = 40 + 5] = 1", get_code_type_alias),
+            ("type foo[**P = 40 + 5] = 1", get_code_type_alias),
+            ("type foo[*Ts = 40 + 5] = 1", get_code_type_alias),
+        ]
+        for snippet, get_code in snippets:
+            c = compile(snippet, "<dummy>", "exec")
+            code = get_code(c)
+            opcodes = list(dis.get_instructions(code))
+            instructions = [opcode.opname for opcode in opcodes]
+            args = [opcode.oparg for opcode in opcodes]
+            self.assertNotIn(40, args)
+            self.assertNotIn(5, args)
+            self.assertIn('LOAD_SMALL_INT', instructions)
+            self.assertIn(45, args)
+
     def test_lineno_procedure_call(self):
         def call():
             (

Lib/test/test_opcache.py

@@ -1666,7 +1666,8 @@ def to_bool_str():
     def test_unpack_sequence(self):
         def unpack_sequence_two_tuple():
             for _ in range(_testinternalcapi.SPECIALIZATION_THRESHOLD):
-                a, b = 1, 2
+                t = 1, 2
+                a, b = t
                 self.assertEqual(a, 1)
                 self.assertEqual(b, 2)
 
@@ -1677,8 +1678,11 @@ def unpack_sequence_two_tuple():
 
         def unpack_sequence_tuple():
             for _ in range(_testinternalcapi.SPECIALIZATION_THRESHOLD):
-                a, = 1,
+                a, b, c, d = 1, 2, 3, 4
                 self.assertEqual(a, 1)
+                self.assertEqual(b, 2)
+                self.assertEqual(c, 3)
+                self.assertEqual(d, 4)
 
         unpack_sequence_tuple()
         self.assert_specialized(unpack_sequence_tuple, "UNPACK_SEQUENCE_TUPLE")

Lib/test/test_peepholer.py

@@ -154,7 +154,7 @@ def test_folding_of_tuples_of_constants(self):
         for line, elem in (
             ('a = 1,2,3', (1, 2, 3)),
             ('("a","b","c")', ('a', 'b', 'c')),
-            ('a,b,c = 1,2,3', (1, 2, 3)),
+            ('a,b,c,d = 1,2,3,4', (1, 2, 3, 4)),
             ('(None, 1, None)', (None, 1, None)),
             ('((1, 2), 3, 4)', ((1, 2), 3, 4)),
             ):
@@ -1349,6 +1349,111 @@ def test_fold_tuple_of_constants(self):
         ]
         self.cfg_optimization_test(same, same, consts=[])
 
+    def test_fold_constant_intrinsic_list_to_tuple(self):
+        INTRINSIC_LIST_TO_TUPLE = 6
+
+        # long tuple
+        consts = 1000
+        before = (
+            [('BUILD_LIST', 0, 0)] +
+            [('LOAD_CONST', 0, 0), ('LIST_APPEND', 1, 0)] * consts +
+            [('CALL_INTRINSIC_1', INTRINSIC_LIST_TO_TUPLE, 0), ('RETURN_VALUE', None, 0)]
+        )
+        after = [
+            ('LOAD_CONST', 1, 0),
+            ('RETURN_VALUE', None, 0)
+        ]
+        result_const = tuple(["test"] * consts)
+        self.cfg_optimization_test(before, after, consts=["test"], expected_consts=["test", result_const])
+
+        # empty list
+        before = [
+            ('BUILD_LIST', 0, 0),
+            ('CALL_INTRINSIC_1', INTRINSIC_LIST_TO_TUPLE, 0),
+            ('RETURN_VALUE', None, 0)
+        ]
+        after = [
+            ('LOAD_CONST', 0, 0),
+            ('RETURN_VALUE', None, 0)
+        ]
+        self.cfg_optimization_test(before, after, consts=[], expected_consts=[()])
+
+        # multiple BUILD_LIST 0: ([], 1, [], 2)
+        same = [
+            ('BUILD_LIST', 0, 0),
+            ('BUILD_LIST', 0, 0),
+            ('LIST_APPEND', 1, 0),
+            ('LOAD_SMALL_INT', 1, 0),
+            ('LIST_APPEND', 1, 0),
+            ('BUILD_LIST', 0, 0),
+            ('LIST_APPEND', 1, 0),
+            ('LOAD_SMALL_INT', 2, 0),
+            ('LIST_APPEND', 1, 0),
+            ('CALL_INTRINSIC_1', INTRINSIC_LIST_TO_TUPLE, 0),
+            ('RETURN_VALUE', None, 0)
+        ]
+        self.cfg_optimization_test(same, same, consts=[])
+
+        # nested folding: (1, 1+1, 3)
+        before = [
+            ('BUILD_LIST', 0, 0),
+            ('LOAD_SMALL_INT', 1, 0),
+            ('LIST_APPEND', 1, 0),
+            ('LOAD_SMALL_INT', 1, 0),
+            ('LOAD_SMALL_INT', 1, 0),
+            ('BINARY_OP', get_binop_argval('NB_ADD'), 0),
+            ('LIST_APPEND', 1, 0),
+            ('LOAD_SMALL_INT', 3, 0),
+            ('LIST_APPEND', 1, 0),
+            ('CALL_INTRINSIC_1', INTRINSIC_LIST_TO_TUPLE, 0),
+            ('RETURN_VALUE', None, 0)
+        ]
+        after = [
+            ('LOAD_CONST', 0, 0),
+            ('RETURN_VALUE', None, 0)
+        ]
+        self.cfg_optimization_test(before, after, consts=[], expected_consts=[(1, 2, 3)])
+
+        # NOP's in between: (1, 2, 3)
+        before = [
+            ('BUILD_LIST', 0, 0),
+            ('NOP', None, 0),
+            ('LOAD_SMALL_INT', 1, 0),
+            ('NOP', None, 0),
+            ('NOP', None, 0),
+            ('LIST_APPEND', 1, 0),
+            ('NOP', None, 0),
+            ('LOAD_SMALL_INT', 2, 0),
+            ('NOP', None, 0),
+            ('NOP', None, 0),
+            ('LIST_APPEND', 1, 0),
+            ('NOP', None, 0),
+            ('LOAD_SMALL_INT', 3, 0),
+            ('NOP', None, 0),
+            ('LIST_APPEND', 1, 0),
+            ('NOP', None, 0),
+            ('CALL_INTRINSIC_1', INTRINSIC_LIST_TO_TUPLE, 0),
+            ('RETURN_VALUE', None, 0)
+        ]
+        after = [
+            ('LOAD_CONST', 0, 0),
+            ('RETURN_VALUE', None, 0)
+        ]
+        self.cfg_optimization_test(before, after, consts=[], expected_consts=[(1, 2, 3)])
+
+        # no sequence start
+        same = [
+            ('LOAD_SMALL_INT', 1, 0),
+            ('LIST_APPEND', 1, 0),
+            ('LOAD_SMALL_INT', 2, 0),
+            ('LIST_APPEND', 1, 0),
+            ('LOAD_SMALL_INT', 3, 0),
+            ('LIST_APPEND', 1, 0),
+            ('CALL_INTRINSIC_1', INTRINSIC_LIST_TO_TUPLE, 0),
+            ('RETURN_VALUE', None, 0)
+        ]
+        self.cfg_optimization_test(same, same, consts=[])
+
     def test_optimize_if_const_list(self):
         before = [
             ('NOP', None, 0),