Mark Dickinson added the comment:

> I don't think fixing bugs on a specific architecture counts as a new feature.

It's not really a bugfix, though.  Python 3.4 *should* (I'm not in a position 
to check, but Andreas may be) be behaving as designed on m68k: the configure 
script will correctly determine that there's a potential issue with double 
rounding, and since it doesn't currently know of any way to control the FPU 
precision setting on m68k, it'll set the environment variables up so that the 
legacy floating-point repr code is used.  The built Python should function as 
normal, expect that sys.float_repr_style will be 'legacy' instead of 'short', 
and we won't get the (primarily cosmetic) benefits of the short float repr.

This patch then changes the part where Python doesn't know how to change the 
precision, allowing it to use David Gay's short float repr code instead of the 
legacy code.  So I see it as an enhancement rather than a bugfix.

And this would actually be a somewhat significant behaviour change: on m68k 
with Python 3.4.0, we'd see:

>>> 1.1
1.1000000000000001

and (if this patch went into the 3.4 branch), on Python 3.4.1 we'd see instead:

>>> 1.1
1.1

The behaviour of string formatting and the round function would also change in 
edge cases.

There's an argument that the number of users affected by this change is likely 
to be tiny, so changing this in 3.4.1 is unlikely to break people's code.  But 
the tininess of the userbase is equally the basis of an argument that the 
change isn't at all urgent, and those affected can wait for Python 3.5 or patch 
their copy of Python; I don't see a really good reason to break the policy 
about new features on bugfix branches for this particular issue.

Given all that, I don't think it would be appropriate to include the change in 
Python 3.4.1.  I'd personally like to see it go into Python 3.5, but that's 
dependent on the outcome of the "we don't accept patches for unsupported 
platforms" discussion (which is orthogonal to the 'is this an enhancement or a 
bugfix' discussion).

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<http://bugs.python.org/issue20904>
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