diff options
Diffstat (limited to 'Lib/test/test_int.py')
| -rw-r--r-- | Lib/test/test_int.py | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/Lib/test/test_int.py b/Lib/test/test_int.py index ce18ad2..514a98e 100644 --- a/Lib/test/test_int.py +++ b/Lib/test/test_int.py @@ -275,6 +275,40 @@ class IntTestCases(unittest.TestCase): self.assertEqual((a+1).bit_length(), i+1) self.assertEqual((-a-1).bit_length(), i+1) + @unittest.skipUnless(float.__getformat__("double").startswith("IEEE"), + "test requires IEEE 754 doubles") + def test_float_conversion(self): + # values exactly representable as floats + exact_values = [-2, -1, 0, 1, 2, 2**52, 2**53-1, 2**53, 2**53+2, + 2**53+4, 2**54-4, 2**54-2, 2**63, -2**63, 2**64, + -2**64, 10**20, 10**21, 10**22] + for value in exact_values: + self.assertEqual(int(float(int(value))), value) + + # test round-half-to-even + self.assertEqual(int(float(2**53+1)), 2**53) + self.assertEqual(int(float(2**53+2)), 2**53+2) + self.assertEqual(int(float(2**53+3)), 2**53+4) + self.assertEqual(int(float(2**53+5)), 2**53+4) + self.assertEqual(int(float(2**53+6)), 2**53+6) + self.assertEqual(int(float(2**53+7)), 2**53+8) + + self.assertEqual(int(float(-2**53-1)), -2**53) + self.assertEqual(int(float(-2**53-2)), -2**53-2) + self.assertEqual(int(float(-2**53-3)), -2**53-4) + self.assertEqual(int(float(-2**53-5)), -2**53-4) + self.assertEqual(int(float(-2**53-6)), -2**53-6) + self.assertEqual(int(float(-2**53-7)), -2**53-8) + + self.assertEqual(int(float(2**54-2)), 2**54-2) + self.assertEqual(int(float(2**54-1)), 2**54) + self.assertEqual(int(float(2**54+2)), 2**54) + self.assertEqual(int(float(2**54+3)), 2**54+4) + self.assertEqual(int(float(2**54+5)), 2**54+4) + self.assertEqual(int(float(2**54+6)), 2**54+8) + self.assertEqual(int(float(2**54+10)), 2**54+8) + self.assertEqual(int(float(2**54+11)), 2**54+12) + def test_intconversion(self): # Test __int__() class ClassicMissingMethods: |