test_peepholer.py 文件源码

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)