diff options
Diffstat (limited to 'Lib/test/test_long.py')
| -rw-r--r-- | Lib/test/test_long.py | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/Lib/test/test_long.py b/Lib/test/test_long.py index 0e07090..92285b2 100644 --- a/Lib/test/test_long.py +++ b/Lib/test/test_long.py @@ -15,7 +15,7 @@ class Frm(object): return self.format % self.args # SHIFT should match the value in longintrepr.h for best testing. -SHIFT = 15 +SHIFT = sys.int_info.bits_per_digit BASE = 2 ** SHIFT MASK = BASE - 1 KARATSUBA_CUTOFF = 70 # from longobject.c @@ -120,6 +120,35 @@ class LongTest(unittest.TestCase): y = self.getran(leny) or 1 self.check_division(x, y) + # specific numbers chosen to exercise corner cases of the + # current long division implementation + + # 30-bit cases involving a quotient digit estimate of BASE+1 + self.check_division(1231948412290879395966702881, + 1147341367131428698) + self.check_division(815427756481275430342312021515587883, + 707270836069027745) + self.check_division(627976073697012820849443363563599041, + 643588798496057020) + self.check_division(1115141373653752303710932756325578065, + 1038556335171453937726882627) + # 30-bit cases that require the post-subtraction correction step + self.check_division(922498905405436751940989320930368494, + 949985870686786135626943396) + self.check_division(768235853328091167204009652174031844, + 1091555541180371554426545266) + + # 15-bit cases involving a quotient digit estimate of BASE+1 + self.check_division(20172188947443, 615611397) + self.check_division(1020908530270155025, 950795710) + self.check_division(128589565723112408, 736393718) + self.check_division(609919780285761575, 18613274546784) + # 15-bit cases that require the post-subtraction correction step + self.check_division(710031681576388032, 26769404391308) + self.check_division(1933622614268221, 30212853348836) + + + def test_karatsuba(self): digits = list(range(1, 5)) + list(range(KARATSUBA_CUTOFF, KARATSUBA_CUTOFF + 10)) |