/Lib/test/test_peepholer.py
Python | 336 lines | 324 code | 7 blank | 5 comment | 16 complexity | 218ad5e20a3d37c1cde186e1e0fa54f8 MD5 | raw file
- import dis
- import unittest
- from test.bytecode_helper import BytecodeTestCase
- class TestTranforms(BytecodeTestCase):
- def test_unot(self):
- # UNARY_NOT POP_JUMP_IF_FALSE --> POP_JUMP_IF_TRUE'
- def unot(x):
- if not x == 2:
- del x
- self.assertNotInBytecode(unot, 'UNARY_NOT')
- self.assertNotInBytecode(unot, 'POP_JUMP_IF_FALSE')
- self.assertInBytecode(unot, 'POP_JUMP_IF_TRUE')
- 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',),
- ):
- code = compile(line, '', 'single')
- self.assertInBytecode(code, 'COMPARE_OP', cmp_op)
- def test_global_as_constant(self):
- # LOAD_GLOBAL None/True/False --> LOAD_CONST None/True/False
- def f():
- x = None
- x = None
- return x
- def g():
- x = True
- return x
- def h():
- x = False
- return x
- for func, elem in ((f, None), (g, True), (h, False)):
- self.assertNotInBytecode(func, 'LOAD_GLOBAL')
- self.assertInBytecode(func, 'LOAD_CONST', elem)
- def f():
- 'Adding a docstring made this test fail in Py2.5.0'
- return None
- self.assertNotInBytecode(f, 'LOAD_GLOBAL')
- self.assertInBytecode(f, 'LOAD_CONST', None)
- def test_while_one(self):
- # Skip over: LOAD_CONST trueconst POP_JUMP_IF_FALSE xx
- def f():
- while 1:
- pass
- return list
- for elem in ('LOAD_CONST', 'POP_JUMP_IF_FALSE'):
- self.assertNotInBytecode(f, elem)
- for elem in ('JUMP_ABSOLUTE',):
- self.assertInBytecode(f, elem)
- def test_pack_unpack(self):
- for line, elem in (
- ('a, = a,', 'LOAD_CONST',),
- ('a, b = a, b', 'ROT_TWO',),
- ('a, b, c = a, b, c', 'ROT_THREE',),
- ):
- code = compile(line,'','single')
- self.assertInBytecode(code, elem)
- self.assertNotInBytecode(code, 'BUILD_TUPLE')
- self.assertNotInBytecode(code, 'UNPACK_TUPLE')
- 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)),
- ('(None, 1, None)', (None, 1, None)),
- ('((1, 2), 3, 4)', ((1, 2), 3, 4)),
- ):
- code = compile(line,'','single')
- self.assertInBytecode(code, 'LOAD_CONST', elem)
- self.assertNotInBytecode(code, 'BUILD_TUPLE')
- # Long tuples should be folded too.
- code = compile(repr(tuple(range(10000))),'','single')
- self.assertNotInBytecode(code, 'BUILD_TUPLE')
- # One LOAD_CONST for the tuple, one for the None return value
- load_consts = [instr for instr in dis.get_instructions(code)
- if instr.opname == 'LOAD_CONST']
- self.assertEqual(len(load_consts), 2)
- # Bug 1053819: Tuple of constants misidentified when presented with:
- # . . . opcode_with_arg 100 unary_opcode BUILD_TUPLE 1 . . .
- # The following would segfault upon compilation
- def crater():
- (~[
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- ],)
- def test_folding_of_lists_of_constants(self):
- for line, elem in (
- # in/not in constants with BUILD_LIST should be folded to a tuple:
- ('a in [1,2,3]', (1, 2, 3)),
- ('a not in ["a","b","c"]', ('a', 'b', 'c')),
- ('a in [None, 1, None]', (None, 1, None)),
- ('a not in [(1, 2), 3, 4]', ((1, 2), 3, 4)),
- ):
- code = compile(line, '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', elem)
- self.assertNotInBytecode(code, 'BUILD_LIST')
- def test_folding_of_sets_of_constants(self):
- for line, elem in (
- # in/not in constants with BUILD_SET should be folded to a frozenset:
- ('a in {1,2,3}', frozenset({1, 2, 3})),
- ('a not in {"a","b","c"}', frozenset({'a', 'c', 'b'})),
- ('a in {None, 1, None}', frozenset({1, None})),
- ('a not in {(1, 2), 3, 4}', frozenset({(1, 2), 3, 4})),
- ('a in {1, 2, 3, 3, 2, 1}', frozenset({1, 2, 3})),
- ):
- code = compile(line, '', 'single')
- self.assertNotInBytecode(code, 'BUILD_SET')
- self.assertInBytecode(code, 'LOAD_CONST', elem)
- # Ensure that the resulting code actually works:
- def f(a):
- return a in {1, 2, 3}
- def g(a):
- return a not in {1, 2, 3}
- self.assertTrue(f(3))
- self.assertTrue(not f(4))
- self.assertTrue(not g(3))
- self.assertTrue(g(4))
- def test_folding_of_binops_on_constants(self):
- for line, elem in (
- ('a = 2+3+4', 9), # chained fold
- ('"@"*4', '@@@@'), # check string ops
- ('a="abc" + "def"', 'abcdef'), # check string ops
- ('a = 3**4', 81), # binary power
- ('a = 3*4', 12), # binary multiply
- ('a = 13//4', 3), # binary floor divide
- ('a = 14%4', 2), # binary modulo
- ('a = 2+3', 5), # binary add
- ('a = 13-4', 9), # binary subtract
- ('a = (12,13)[1]', 13), # binary subscr
- ('a = 13 << 2', 52), # binary lshift
- ('a = 13 >> 2', 3), # binary rshift
- ('a = 13 & 7', 5), # binary and
- ('a = 13 ^ 7', 10), # binary xor
- ('a = 13 | 7', 15), # binary or
- ):
- code = compile(line, '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', elem)
- for instr in dis.get_instructions(code):
- self.assertFalse(instr.opname.startswith('BINARY_'))
- # Verify that unfoldables are skipped
- code = compile('a=2+"b"', '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', 2)
- self.assertInBytecode(code, 'LOAD_CONST', 'b')
- # Verify that large sequences do not result from folding
- code = compile('a="x"*10000', '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', 10000)
- self.assertNotIn("x"*10000, code.co_consts)
- code = compile('a=1<<1000', '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', 1000)
- self.assertNotIn(1<<1000, code.co_consts)
- code = compile('a=2**1000', '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', 1000)
- self.assertNotIn(2**1000, code.co_consts)
- def test_binary_subscr_on_unicode(self):
- # valid code get optimized
- code = compile('"foo"[0]', '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', 'f')
- self.assertNotInBytecode(code, 'BINARY_SUBSCR')
- code = compile('"\u0061\uffff"[1]', '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', '\uffff')
- self.assertNotInBytecode(code,'BINARY_SUBSCR')
- # With PEP 393, non-BMP char get optimized
- code = compile('"\U00012345"[0]', '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', '\U00012345')
- self.assertNotInBytecode(code, 'BINARY_SUBSCR')
- # invalid code doesn't get optimized
- # out of range
- code = compile('"fuu"[10]', '', 'single')
- self.assertInBytecode(code, 'BINARY_SUBSCR')
- def test_folding_of_unaryops_on_constants(self):
- for line, elem in (
- ('-0.5', -0.5), # unary negative
- ('-0.0', -0.0), # -0.0
- ('-(1.0-1.0)', -0.0), # -0.0 after folding
- ('-0', 0), # -0
- ('~-2', 1), # unary invert
- ('+1', 1), # unary positive
- ):
- code = compile(line, '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', elem)
- for instr in dis.get_instructions(code):
- self.assertFalse(instr.opname.startswith('UNARY_'))
- # Check that -0.0 works after marshaling
- def negzero():
- return -(1.0-1.0)
- for instr in dis.get_instructions(code):
- self.assertFalse(instr.opname.startswith('UNARY_'))
- # Verify that unfoldables are skipped
- for line, elem, opname in (
- ('-"abc"', 'abc', 'UNARY_NEGATIVE'),
- ('~"abc"', 'abc', 'UNARY_INVERT'),
- ):
- code = compile(line, '', 'single')
- self.assertInBytecode(code, 'LOAD_CONST', elem)
- self.assertInBytecode(code, opname)
- def test_elim_extra_return(self):
- # RETURN LOAD_CONST None RETURN --> RETURN
- def f(x):
- return x
- self.assertNotInBytecode(f, 'LOAD_CONST', None)
- returns = [instr for instr in dis.get_instructions(f)
- if instr.opname == 'RETURN_VALUE']
- self.assertEqual(len(returns), 1)
- def test_elim_jump_to_return(self):
- # JUMP_FORWARD to RETURN --> RETURN
- def f(cond, true_value, false_value):
- return true_value if cond else false_value
- self.assertNotInBytecode(f, 'JUMP_FORWARD')
- self.assertNotInBytecode(f, 'JUMP_ABSOLUTE')
- returns = [instr for instr in dis.get_instructions(f)
- if instr.opname == 'RETURN_VALUE']
- self.assertEqual(len(returns), 2)
- def test_elim_jump_after_return1(self):
- # Eliminate dead code: jumps immediately after returns can't be reached
- def f(cond1, cond2):
- if cond1: return 1
- if cond2: return 2
- while 1:
- return 3
- while 1:
- if cond1: return 4
- return 5
- return 6
- self.assertNotInBytecode(f, 'JUMP_FORWARD')
- self.assertNotInBytecode(f, 'JUMP_ABSOLUTE')
- returns = [instr for instr in dis.get_instructions(f)
- if instr.opname == 'RETURN_VALUE']
- self.assertEqual(len(returns), 6)
- def test_elim_jump_after_return2(self):
- # Eliminate dead code: jumps immediately after returns can't be reached
- def f(cond1, cond2):
- while 1:
- if cond1: return 4
- self.assertNotInBytecode(f, 'JUMP_FORWARD')
- # There should be one jump for the while loop.
- returns = [instr for instr in dis.get_instructions(f)
- if instr.opname == 'JUMP_ABSOLUTE']
- self.assertEqual(len(returns), 1)
- returns = [instr for instr in dis.get_instructions(f)
- if instr.opname == 'RETURN_VALUE']
- self.assertEqual(len(returns), 2)
- def test_make_function_doesnt_bail(self):
- def f():
- def g()->1+1:
- pass
- return g
- self.assertNotInBytecode(f, 'BINARY_ADD')
- def test_constant_folding(self):
- # Issue #11244: aggressive constant folding.
- exprs = [
- '3 * -5',
- '-3 * 5',
- '2 * (3 * 4)',
- '(2 * 3) * 4',
- '(-1, 2, 3)',
- '(1, -2, 3)',
- '(1, 2, -3)',
- '(1, 2, -3) * 6',
- 'lambda x: x in {(3 * -5) + (-1 - 6), (1, -2, 3) * 2, None}',
- ]
- for e in exprs:
- code = compile(e, '', 'single')
- for instr in dis.get_instructions(code):
- self.assertFalse(instr.opname.startswith('UNARY_'))
- self.assertFalse(instr.opname.startswith('BINARY_'))
- self.assertFalse(instr.opname.startswith('BUILD_'))
- def test_condition_with_binop_with_bools(self):
- def f():
- if True or False:
- return 1
- return 0
- self.assertEqual(f(), 1)
- class TestBuglets(unittest.TestCase):
- def test_bug_11510(self):
- # folded constant set optimization was commingled with the tuple
- # unpacking optimization which would fail if the set had duplicate
- # elements so that the set length was unexpected
- def f():
- x, y = {1, 1}
- return x, y
- with self.assertRaises(ValueError):
- f()
- if __name__ == "__main__":
- unittest.main()