bpo-32925: Optimized iterating and containing test for literal lists (GH-5842)

consisting of non-constants: `x in [a, b]` and `for x in [a, b]`.
The case of all constant elements already was optimized.

1 files changed, 24 insertions, 0 deletions

diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py
index c24cf77..794d104 100644
--- a/Lib/test/test_peepholer.py
+++ b/Lib/test/test_peepholer.py
@@ -3,6 +3,19 @@ import unittest
 
 from test.bytecode_helper import BytecodeTestCase
 
+def count_instr_recursively(f, opname):
+    count = 0
+    for instr in dis.get_instructions(f):
+        if instr.opname == opname:
+            count += 1
+    if hasattr(f, '__code__'):
+        f = f.__code__
+    for c in f.co_consts:
+        if hasattr(c, 'co_code'):
+            count += count_instr_recursively(c, opname)
+    return count
+
+
 class TestTranforms(BytecodeTestCase):
 
     def test_unot(self):
@@ -311,6 +324,17 @@ class TestTranforms(BytecodeTestCase):
                 self.assertFalse(instr.opname.startswith('BINARY_'))
                 self.assertFalse(instr.opname.startswith('BUILD_'))
 
+    def test_in_literal_list(self):
+        def containtest():
+            return x in [a, b]
+        self.assertEqual(count_instr_recursively(containtest, 'BUILD_LIST'), 0)
+
+    def test_iterate_literal_list(self):
+        def forloop():
+            for x in [a, b]:
+                pass
+        self.assertEqual(count_instr_recursively(forloop, 'BUILD_LIST'), 0)
+
 
 class TestBuglets(unittest.TestCase):