[issue27761] Private _nth_root function loses accuracy on PowerPC

[Steven D'Aprano]

Steven D'Aprano added the comment:

Tests fail on a Power PC buildbot:

http://buildbot.python.org/all/builders/PPC64LE%20Fedora%203.x/builds/1476/steps/test/logs/stdio
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FAIL: testExactPowers (test.test_statistics.Test_Nth_Root) (i=29, n=11)
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Traceback (most recent call last):
  File "/home/shager/cpython-buildarea/3.x.edelsohn-fedora-ppc64le/build/Lib/test/test_statistics.py", line 1216, in testExactPowers
    self.assertEqual(self.nroot(x, n), i)
AssertionError: 29.000000000000004 != 29

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FAIL: testExactPowersNegatives (test.test_statistics.Test_Nth_Root) (i=-29, n=11)
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Traceback (most recent call last):
  File "/home/shager/cpython-buildarea/3.x.edelsohn-fedora-ppc64le/build/Lib/test/test_statistics.py", line 1228, in testExactPowersNegatives
    self.assertEqual(self.nroot(x, n), i)
AssertionError: -29.000000000000004 != -29

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue27761>
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