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Use skipUnless to skip math module tests on non-IEEE 754 platforms.

This commit is contained in:
Mark Dickinson 2009-09-18 21:01:50 +00:00
parent 6be522bfc2
commit 2985dbb526
1 changed files with 34 additions and 31 deletions
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65
Lib/test/test_math.py
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@ -13,6 +13,11 @@ NAN = float('nan')
INF = float('inf')
NINF = float('-inf')
# decorator for skipping tests on non-IEEE 754 platforms
requires_IEEE_754 = unittest.skipUnless(
float.__getformat__("double").startswith("IEEE"),
"test requires IEEE 754 doubles")
# detect evidence of double-rounding: fsum is not always correctly
# rounded on machines that suffer from double rounding.
x, y = 1e16, 2.9999 # use temporary values to defeat peephole optimizer
@ -212,33 +217,33 @@ class MathTests(unittest.TestCase):
self.assertRaises(TypeError, math.ceil, t)
self.assertRaises(TypeError, math.ceil, t, 0)
if float.__getformat__("double").startswith("IEEE"):
def testCopysign(self):
self.assertRaises(TypeError, math.copysign)
# copysign should let us distinguish signs of zeros
self.assertEquals(copysign(1., 0.), 1.)
self.assertEquals(copysign(1., -0.), -1.)
self.assertEquals(copysign(INF, 0.), INF)
self.assertEquals(copysign(INF, -0.), NINF)
self.assertEquals(copysign(NINF, 0.), INF)
self.assertEquals(copysign(NINF, -0.), NINF)
# and of infinities
self.assertEquals(copysign(1., INF), 1.)
self.assertEquals(copysign(1., NINF), -1.)
self.assertEquals(copysign(INF, INF), INF)
self.assertEquals(copysign(INF, NINF), NINF)
self.assertEquals(copysign(NINF, INF), INF)
self.assertEquals(copysign(NINF, NINF), NINF)
self.assertTrue(math.isnan(copysign(NAN, 1.)))
self.assertTrue(math.isnan(copysign(NAN, INF)))
self.assertTrue(math.isnan(copysign(NAN, NINF)))
self.assertTrue(math.isnan(copysign(NAN, NAN)))
# copysign(INF, NAN) may be INF or it may be NINF, since
# we don't know whether the sign bit of NAN is set on any
# given platform.
self.assertTrue(math.isinf(copysign(INF, NAN)))
# similarly, copysign(2., NAN) could be 2. or -2.
self.assertEquals(abs(copysign(2., NAN)), 2.)
@requires_IEEE_754
def testCopysign(self):
self.assertRaises(TypeError, math.copysign)
# copysign should let us distinguish signs of zeros
self.assertEquals(copysign(1., 0.), 1.)
self.assertEquals(copysign(1., -0.), -1.)
self.assertEquals(copysign(INF, 0.), INF)
self.assertEquals(copysign(INF, -0.), NINF)
self.assertEquals(copysign(NINF, 0.), INF)
self.assertEquals(copysign(NINF, -0.), NINF)
# and of infinities
self.assertEquals(copysign(1., INF), 1.)
self.assertEquals(copysign(1., NINF), -1.)
self.assertEquals(copysign(INF, INF), INF)
self.assertEquals(copysign(INF, NINF), NINF)
self.assertEquals(copysign(NINF, INF), INF)
self.assertEquals(copysign(NINF, NINF), NINF)
self.assertTrue(math.isnan(copysign(NAN, 1.)))
self.assertTrue(math.isnan(copysign(NAN, INF)))
self.assertTrue(math.isnan(copysign(NAN, NINF)))
self.assertTrue(math.isnan(copysign(NAN, NAN)))
# copysign(INF, NAN) may be INF or it may be NINF, since
# we don't know whether the sign bit of NAN is set on any
# given platform.
self.assertTrue(math.isinf(copysign(INF, NAN)))
# similarly, copysign(2., NAN) could be 2. or -2.
self.assertEquals(abs(copysign(2., NAN)), 2.)
def testCos(self):
self.assertRaises(TypeError, math.cos)
@ -369,8 +374,7 @@ class MathTests(unittest.TestCase):
self.assertEquals(math.frexp(NINF)[0], NINF)
self.assertTrue(math.isnan(math.frexp(NAN)[0]))
@unittest.skipUnless(float.__getformat__("double").startswith("IEEE"),
"test requires IEEE 754 doubles")
@requires_IEEE_754
@unittest.skipIf(HAVE_DOUBLE_ROUNDING,
"fsum is not exact on machines with double rounding")
def testFsum(self):
@ -860,9 +864,8 @@ class MathTests(unittest.TestCase):
else:
self.fail("sqrt(-1) didn't raise ValueError")
@requires_IEEE_754
def test_testfile(self):
if not float.__getformat__("double").startswith("IEEE"):
return
for id, fn, ar, ai, er, ei, flags in parse_testfile(test_file):
# Skip if either the input or result is complex, or if
# flags is nonempty