bpo-39156: Break up COMPARE_OP into four logically distinct opcodes. (GH-17754)

Break up COMPARE_OP into four logically distinct opcodes:
* COMPARE_OP for rich comparisons
* IS_OP for 'is' and 'is not' tests
* CONTAINS_OP for 'in' and 'is not' tests
* JUMP_IF_NOT_EXC_MATCH for checking exceptions in 'try-except' statements.

5 files changed, 86 insertions, 83 deletions

diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py
index d62c6cb..b86612b 100644
--- a/Lib/importlib/_bootstrap_external.py
+++ b/Lib/importlib/_bootstrap_external.py
@@ -274,6 +274,7 @@ _code_type = type(_write_atomic.__code__)
 #     Python 3.9a0  3420 (add LOAD_ASSERTION_ERROR #34880)
 #     Python 3.9a0  3421 (simplified bytecode for with blocks #32949)
 #     Python 3.9a0  3422 (remove BEGIN_FINALLY, END_FINALLY, CALL_FINALLY, POP_FINALLY bytecodes #33387)
+#     Python 3.9a2  3423 (add IS_OP, CONTAINS_OP and JUMP_IF_NOT_EXC_MATCH bytecodes #39156)
 #
 # MAGIC must change whenever the bytecode emitted by the compiler may no
 # longer be understood by older implementations of the eval loop (usually
@@ -282,7 +283,7 @@ _code_type = type(_write_atomic.__code__)
 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
 # in PC/launcher.c must also be updated.
 
-MAGIC_NUMBER = (3422).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3423).to_bytes(2, 'little') + b'\r\n'
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 
 _PYCACHE = '__pycache__'
diff --git a/Lib/opcode.py b/Lib/opcode.py
index 1898a38..e31563b 100644
--- a/Lib/opcode.py
+++ b/Lib/opcode.py
@@ -21,8 +21,7 @@ try:
 except ImportError:
     pass
 
-cmp_op = ('<', '<=', '==', '!=', '>', '>=', 'in', 'not in', 'is',
-        'is not', 'exception match', 'BAD')
+cmp_op = ('<', '<=', '==', '!=', '>', '>=')
 
 hasconst = []
 hasname = []
@@ -159,6 +158,10 @@ jabs_op('POP_JUMP_IF_TRUE', 115)     # ""
 
 name_op('LOAD_GLOBAL', 116)     # Index in name list
 
+def_op('IS_OP', 117)
+def_op('CONTAINS_OP', 118)
+
+jabs_op('JUMP_IF_NOT_EXC_MATCH', 121)
 jrel_op('SETUP_FINALLY', 122)   # Distance to target address
 
 def_op('LOAD_FAST', 124)        # Local variable number
diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
index 313eefd..ac5836d 100644
--- a/Lib/test/test_dis.py
+++ b/Lib/test/test_dis.py
@@ -278,34 +278,33 @@ dis_traceback = """\
     -->       6 BINARY_TRUE_DIVIDE
               8 POP_TOP
              10 POP_BLOCK
-             12 JUMP_FORWARD            44 (to 58)
+             12 JUMP_FORWARD            42 (to 56)
 
 %3d     >>   14 DUP_TOP
              16 LOAD_GLOBAL              0 (Exception)
-             18 COMPARE_OP              10 (exception match)
-             20 POP_JUMP_IF_FALSE       56
-             22 POP_TOP
-             24 STORE_FAST               0 (e)
-             26 POP_TOP
-             28 SETUP_FINALLY           18 (to 48)
-
-%3d          30 LOAD_FAST                0 (e)
-             32 LOAD_ATTR                1 (__traceback__)
-             34 STORE_FAST               1 (tb)
-             36 POP_BLOCK
-             38 POP_EXCEPT
-             40 LOAD_CONST               0 (None)
-             42 STORE_FAST               0 (e)
-             44 DELETE_FAST              0 (e)
-             46 JUMP_FORWARD            10 (to 58)
-        >>   48 LOAD_CONST               0 (None)
-             50 STORE_FAST               0 (e)
-             52 DELETE_FAST              0 (e)
-             54 RERAISE
-        >>   56 RERAISE
-
-%3d     >>   58 LOAD_FAST                1 (tb)
-             60 RETURN_VALUE
+             18 JUMP_IF_NOT_EXC_MATCH    54
+             20 POP_TOP
+             22 STORE_FAST               0 (e)
+             24 POP_TOP
+             26 SETUP_FINALLY           18 (to 46)
+
+%3d          28 LOAD_FAST                0 (e)
+             30 LOAD_ATTR                1 (__traceback__)
+             32 STORE_FAST               1 (tb)
+             34 POP_BLOCK
+             36 POP_EXCEPT
+             38 LOAD_CONST               0 (None)
+             40 STORE_FAST               0 (e)
+             42 DELETE_FAST              0 (e)
+             44 JUMP_FORWARD            10 (to 56)
+        >>   46 LOAD_CONST               0 (None)
+             48 STORE_FAST               0 (e)
+             50 DELETE_FAST              0 (e)
+             52 RERAISE
+        >>   54 RERAISE
+
+%3d     >>   56 LOAD_FAST                1 (tb)
+             58 RETURN_VALUE
 """ % (TRACEBACK_CODE.co_firstlineno + 1,
        TRACEBACK_CODE.co_firstlineno + 2,
        TRACEBACK_CODE.co_firstlineno + 3,
@@ -506,7 +505,8 @@ class DisTests(unittest.TestCase):
     def test_widths(self):
         for opcode, opname in enumerate(dis.opname):
             if opname in ('BUILD_MAP_UNPACK_WITH_CALL',
-                          'BUILD_TUPLE_UNPACK_WITH_CALL'):
+                          'BUILD_TUPLE_UNPACK_WITH_CALL',
+                          'JUMP_IF_NOT_EXC_MATCH'):
                 continue
             with self.subTest(opname=opname):
                 width = dis._OPNAME_WIDTH
@@ -1045,63 +1045,62 @@ expected_opinfo_jumpy = [
   Instruction(opname='LOAD_CONST', opcode=100, arg=6, argval='Who let lolcatz into this test suite?', argrepr="'Who let lolcatz into this test suite?'", offset=96, starts_line=None, is_jump_target=False),
   Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=98, starts_line=None, is_jump_target=False),
   Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=100, starts_line=None, is_jump_target=False),
-  Instruction(opname='SETUP_FINALLY', opcode=122, arg=98, argval=202, argrepr='to 202', offset=102, starts_line=20, is_jump_target=True),
+  Instruction(opname='SETUP_FINALLY', opcode=122, arg=96, argval=200, argrepr='to 200', offset=102, starts_line=20, is_jump_target=True),
   Instruction(opname='SETUP_FINALLY', opcode=122, arg=12, argval=118, argrepr='to 118', offset=104, starts_line=None, is_jump_target=False),
   Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=106, starts_line=21, is_jump_target=False),
   Instruction(opname='LOAD_CONST', opcode=100, arg=7, argval=0, argrepr='0', offset=108, starts_line=None, is_jump_target=False),
   Instruction(opname='BINARY_TRUE_DIVIDE', opcode=27, arg=None, argval=None, argrepr='', offset=110, starts_line=None, is_jump_target=False),
   Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=112, starts_line=None, is_jump_target=False),
   Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=114, starts_line=None, is_jump_target=False),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=28, argval=146, argrepr='to 146', offset=116, starts_line=None, is_jump_target=False),
+  Instruction(opname='JUMP_FORWARD', opcode=110, arg=26, argval=144, argrepr='to 144', offset=116, starts_line=None, is_jump_target=False),
   Instruction(opname='DUP_TOP', opcode=4, arg=None, argval=None, argrepr='', offset=118, starts_line=22, is_jump_target=True),
   Instruction(opname='LOAD_GLOBAL', opcode=116, arg=2, argval='ZeroDivisionError', argrepr='ZeroDivisionError', offset=120, starts_line=None, is_jump_target=False),
-  Instruction(opname='COMPARE_OP', opcode=107, arg=10, argval='exception match', argrepr='exception match', offset=122, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=144, argval=144, argrepr='', offset=124, starts_line=None, is_jump_target=False),
+  Instruction(opname='JUMP_IF_NOT_EXC_MATCH', opcode=121, arg=142, argval=142, argrepr='', offset=122, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=124, starts_line=None, is_jump_target=False),
   Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=126, starts_line=None, is_jump_target=False),
   Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=128, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=130, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=132, starts_line=23, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=8, argval='Here we go, here we go, here we go...', argrepr="'Here we go, here we go, here we go...'", offset=134, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=136, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=138, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=140, starts_line=None, is_jump_target=False),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=46, argval=190, argrepr='to 190', offset=142, starts_line=None, is_jump_target=False),
-  Instruction(opname='RERAISE', opcode=48, arg=None, argval=None, argrepr='', offset=144, starts_line=None, is_jump_target=True),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=146, starts_line=25, is_jump_target=True),
-  Instruction(opname='SETUP_WITH', opcode=143, arg=24, argval=174, argrepr='to 174', offset=148, starts_line=None, is_jump_target=False),
-  Instruction(opname='STORE_FAST', opcode=125, arg=1, argval='dodgy', argrepr='dodgy', offset=150, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=152, starts_line=26, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=9, argval='Never reach this', argrepr="'Never reach this'", offset=154, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=156, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=158, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=160, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=162, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=130, starts_line=23, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=8, argval='Here we go, here we go, here we go...', argrepr="'Here we go, here we go, here we go...'", offset=132, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=134, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=136, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=138, starts_line=None, is_jump_target=False),
+  Instruction(opname='JUMP_FORWARD', opcode=110, arg=46, argval=188, argrepr='to 188', offset=140, starts_line=None, is_jump_target=False),
+  Instruction(opname='RERAISE', opcode=48, arg=None, argval=None, argrepr='', offset=142, starts_line=None, is_jump_target=True),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=144, starts_line=25, is_jump_target=True),
+  Instruction(opname='SETUP_WITH', opcode=143, arg=24, argval=172, argrepr='to 172', offset=146, starts_line=None, is_jump_target=False),
+  Instruction(opname='STORE_FAST', opcode=125, arg=1, argval='dodgy', argrepr='dodgy', offset=148, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=150, starts_line=26, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=9, argval='Never reach this', argrepr="'Never reach this'", offset=152, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=154, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=156, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=158, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=160, starts_line=None, is_jump_target=False),
+  Instruction(opname='DUP_TOP', opcode=4, arg=None, argval=None, argrepr='', offset=162, starts_line=None, is_jump_target=False),
   Instruction(opname='DUP_TOP', opcode=4, arg=None, argval=None, argrepr='', offset=164, starts_line=None, is_jump_target=False),
-  Instruction(opname='DUP_TOP', opcode=4, arg=None, argval=None, argrepr='', offset=166, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=3, argval=3, argrepr='', offset=168, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=170, starts_line=None, is_jump_target=False),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=16, argval=190, argrepr='to 190', offset=172, starts_line=None, is_jump_target=False),
-  Instruction(opname='WITH_EXCEPT_START', opcode=49, arg=None, argval=None, argrepr='', offset=174, starts_line=None, is_jump_target=True),
-  Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=180, argval=180, argrepr='', offset=176, starts_line=None, is_jump_target=False),
-  Instruction(opname='RERAISE', opcode=48, arg=None, argval=None, argrepr='', offset=178, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=180, starts_line=None, is_jump_target=True),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=3, argval=3, argrepr='', offset=166, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=168, starts_line=None, is_jump_target=False),
+  Instruction(opname='JUMP_FORWARD', opcode=110, arg=16, argval=188, argrepr='to 188', offset=170, starts_line=None, is_jump_target=False),
+  Instruction(opname='WITH_EXCEPT_START', opcode=49, arg=None, argval=None, argrepr='', offset=172, starts_line=None, is_jump_target=True),
+  Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=178, argval=178, argrepr='', offset=174, starts_line=None, is_jump_target=False),
+  Instruction(opname='RERAISE', opcode=48, arg=None, argval=None, argrepr='', offset=176, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=178, starts_line=None, is_jump_target=True),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=180, starts_line=None, is_jump_target=False),
   Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=182, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=184, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=186, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=188, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=190, starts_line=None, is_jump_target=True),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=192, starts_line=28, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=194, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=196, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=198, starts_line=None, is_jump_target=False),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=10, argval=212, argrepr='to 212', offset=200, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=202, starts_line=None, is_jump_target=True),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=204, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=206, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=208, starts_line=None, is_jump_target=False),
-  Instruction(opname='RERAISE', opcode=48, arg=None, argval=None, argrepr='', offset=210, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=212, starts_line=None, is_jump_target=True),
-  Instruction(opname='RETURN_VALUE', opcode=83, arg=None, argval=None, argrepr='', offset=214, starts_line=None, is_jump_target=False)
+  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=184, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=186, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=188, starts_line=None, is_jump_target=True),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=190, starts_line=28, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=192, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=194, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=196, starts_line=None, is_jump_target=False),
+  Instruction(opname='JUMP_FORWARD', opcode=110, arg=10, argval=210, argrepr='to 210', offset=198, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=200, starts_line=None, is_jump_target=True),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=202, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=204, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=206, starts_line=None, is_jump_target=False),
+  Instruction(opname='RERAISE', opcode=48, arg=None, argval=None, argrepr='', offset=208, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=210, starts_line=None, is_jump_target=True),
+  Instruction(opname='RETURN_VALUE', opcode=83, arg=None, argval=None, argrepr='', offset=212, starts_line=None, is_jump_target=False),
 ]
 
 # One last piece of inspect fodder to check the default line number handling
diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py
index 23cc36c..567e6a1 100644
--- a/Lib/test/test_peepholer.py
+++ b/Lib/test/test_peepholer.py
@@ -65,14 +65,14 @@ class TestTranforms(BytecodeTestCase):
         self.check_lnotab(unot)
 
     def test_elim_inversion_of_is_or_in(self):
-        for line, cmp_op in (
-            ('not a is b', 'is not',),
-            ('not a in b', 'not in',),
-            ('not a is not b', 'is',),
-            ('not a not in b', 'in',),
+        for line, cmp_op, invert in (
+            ('not a is b', 'IS_OP', 1,),
+            ('not a is not b', 'IS_OP', 0,),
+            ('not a in b', 'CONTAINS_OP', 1,),
+            ('not a not in b', 'CONTAINS_OP', 0,),
             ):
             code = compile(line, '', 'single')
-            self.assertInBytecode(code, 'COMPARE_OP', cmp_op)
+            self.assertInBytecode(code, cmp_op, invert)
             self.check_lnotab(code)
 
     def test_global_as_constant(self):
diff --git a/Lib/test/test_positional_only_arg.py b/Lib/test/test_positional_only_arg.py
index bf332e5..0a9503e 100644
--- a/Lib/test/test_positional_only_arg.py
+++ b/Lib/test/test_positional_only_arg.py
@@ -434,11 +434,11 @@ class PositionalOnlyTestCase(unittest.TestCase):
             def f(x: not (int is int), /): ...
 
         # without constant folding we end up with
-        # COMPARE_OP(is), UNARY_NOT
-        # with constant folding we should expect a COMPARE_OP(is not)
+        # COMPARE_OP(is), IS_OP (0)
+        # with constant folding we should expect a IS_OP (1)
         codes = [(i.opname, i.argval) for i in dis.get_instructions(g)]
         self.assertNotIn(('UNARY_NOT', None), codes)
-        self.assertIn(('COMPARE_OP', 'is not'), codes)
+        self.assertIn(('IS_OP', 1), codes)
 
 
 if __name__ == "__main__":