[pypy-commit] pypy default: Add comment

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r74343:fb5c0ab7038f
Date: 2014-11-05 17:06 +0100
http://bitbucket.org/pypy/pypy/changeset/fb5c0ab7038f/

Log:	Add comment

diff --git a/rpython/jit/metainterp/history.py b/rpython/jit/metainterp/history.py
--- a/rpython/jit/metainterp/history.py
+++ b/rpython/jit/metainterp/history.py
@@ -279,7 +279,8 @@
             # careful in this comparison: if self.value and other.value
             # are both NaN, stored as regular floats (i.e. on 64-bit),
             # then just using "==" would say False: two NaNs are always
-            # different from each other.
+            # different from each other.  Conversely, "0.0 == -0.0" but
+            # they are not the same constant.
             return (longlong.extract_bits(self.value) ==
                     longlong.extract_bits(other.value))
         return False