[Python-checkins] r87035 - in python/branches/release31-maint: Lib/test/test_float.py Misc/NEWS Objects/floatobject.c
mark.dickinson
python-checkins at python.org
Sat Dec 4 13:42:18 CET 2010
Author: mark.dickinson
Date: Sat Dec 4 13:42:18 2010
New Revision: 87035
Log:
Backout broken backport. (Sorry.)
Modified:
python/branches/release31-maint/ (props changed)
python/branches/release31-maint/Lib/test/test_float.py
python/branches/release31-maint/Misc/NEWS
python/branches/release31-maint/Objects/floatobject.c
Modified: python/branches/release31-maint/Lib/test/test_float.py
==============================================================================
--- python/branches/release31-maint/Lib/test/test_float.py (original)
+++ python/branches/release31-maint/Lib/test/test_float.py Sat Dec 4 13:42:18 2010
@@ -12,6 +12,16 @@
INF = float("inf")
NAN = float("nan")
+have_getformat = hasattr(float, "__getformat__")
+requires_getformat = unittest.skipUnless(have_getformat,
+ "requires __getformat__")
+requires_setformat = unittest.skipUnless(hasattr(float, "__setformat__"),
+ "requires __setformat__")
+# decorator for skipping tests on non-IEEE 754 platforms
+requires_IEEE_754 = unittest.skipUnless(have_getformat and
+ float.__getformat__("double").startswith("IEEE"),
+ "test requires IEEE 754 doubles")
+
#locate file with float format test values
test_dir = os.path.dirname(__file__) or os.curdir
format_testfile = os.path.join(test_dir, 'formatfloat_testcases.txt')
@@ -231,26 +241,6 @@
self.assertTrue(d == d, "{%r : None} not equal to itself" % f)
- @requires_IEEE_754
- def test_float_mod(self):
- # Check behaviour of % operator for IEEE 754 special cases.
- # In particular, check signs of zeros.
- mod = operator.mod
-
- self.assertEqualAndEqualSign(mod(-1.0, 1.0), 0.0)
- self.assertEqualAndEqualSign(mod(-1e-100, 1.0), 1.0)
- self.assertEqualAndEqualSign(mod(-0.0, 1.0), 0.0)
- self.assertEqualAndEqualSign(mod(0.0, 1.0), 0.0)
- self.assertEqualAndEqualSign(mod(1e-100, 1.0), 1e-100)
- self.assertEqualAndEqualSign(mod(1.0, 1.0), 0.0)
-
- self.assertEqualAndEqualSign(mod(-1.0, -1.0), -0.0)
- self.assertEqualAndEqualSign(mod(-1e-100, -1.0), -1e-100)
- self.assertEqualAndEqualSign(mod(-0.0, -1.0), -0.0)
- self.assertEqualAndEqualSign(mod(0.0, -1.0), -0.0)
- self.assertEqualAndEqualSign(mod(1e-100, -1.0), -1.0)
- self.assertEqualAndEqualSign(mod(1.0, -1.0), -0.0)
-
class FormatFunctionsTestCase(unittest.TestCase):
Modified: python/branches/release31-maint/Misc/NEWS
==============================================================================
--- python/branches/release31-maint/Misc/NEWS (original)
+++ python/branches/release31-maint/Misc/NEWS Sat Dec 4 13:42:18 2010
@@ -10,10 +10,6 @@
Core and Builtins
-----------------
-- Issue #10596: Fix float.__mod__ to have the same behaviour as
- float.__divmod__ with respect to signed zeros. -4.0 % 4.0 should be
- 0.0, not -0.0.
-
Library
-------
Modified: python/branches/release31-maint/Objects/floatobject.c
==============================================================================
--- python/branches/release31-maint/Objects/floatobject.c (original)
+++ python/branches/release31-maint/Objects/floatobject.c Sat Dec 4 13:42:18 2010
@@ -600,20 +600,10 @@
#endif
PyFPE_START_PROTECT("modulo", return 0)
mod = fmod(vx, wx);
- if (mod) {
- /* ensure the remainder has the same sign as the denominator */
- if ((wx < 0) != (mod < 0)) {
- mod += wx;
- }
- }
- else {
- /* the remainder is zero, and in the presence of signed zeroes
- fmod returns different results across platforms; ensure
- it has the same sign as the denominator; we'd like to do
- "mod = wx * 0.0", but that may get optimized away */
- mod *= mod; /* hide "mod = +0" from optimizer */
- if (wx < 0.0)
- mod = -mod;
+ /* note: checking mod*wx < 0 is incorrect -- underflows to
+ 0 if wx < sqrt(smallest nonzero double) */
+ if (mod && ((wx < 0) != (mod < 0))) {
+ mod += wx;
}
PyFPE_END_PROTECT(mod)
return PyFloat_FromDouble(mod);
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