Issue #10337: skip tests of tanh() sign in test_math and test_cmath if tanh()
doesn't preserve the zero sign (if TANH_PRESERVES_ZERO_SIGN define is 0).
diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index 1499ff9..b7a516c 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -8,6 +8,7 @@
import sys
import random
import struct
+import sysconfig
eps = 1E-05
NAN = float('nan')
@@ -891,11 +892,15 @@
self.ftest('tanh(inf)', math.tanh(INF), 1)
self.ftest('tanh(-inf)', math.tanh(NINF), -1)
self.assertTrue(math.isnan(math.tanh(NAN)))
+
+ @requires_IEEE_754
+ @unittest.skipIf(sysconfig.get_config_var('TANH_PRESERVES_ZERO_SIGN') == 0,
+ "system tanh() function doesn't copy the sign")
+ def testTanhSign(self):
# check that tanh(-0.) == -0. on IEEE 754 systems
- if float.__getformat__("double").startswith("IEEE"):
- self.assertEqual(math.tanh(-0.), -0.)
- self.assertEqual(math.copysign(1., math.tanh(-0.)),
- math.copysign(1., -0.))
+ self.assertEqual(math.tanh(-0.), -0.)
+ self.assertEqual(math.copysign(1., math.tanh(-0.)),
+ math.copysign(1., -0.))
def test_trunc(self):
self.assertEqual(math.trunc(1), 1)
@@ -1008,8 +1013,7 @@
self.fail(message)
self.ftest("%s:%s(%r)" % (id, fn, ar), result, er)
- @unittest.skipUnless(float.__getformat__("double").startswith("IEEE"),
- "test requires IEEE 754 doubles")
+ @requires_IEEE_754
def test_mtestfile(self):
ALLOWED_ERROR = 20 # permitted error, in ulps
fail_fmt = "{}:{}({!r}): expected {!r}, got {!r}"