[Python-Dev] alpha problems -- need input

[Tim Peters]

Disabling a test on a platform is usually a bad thing, overall.  The
purpose of the test suite isn't to get a lot of green buildbot boxes
<0.5 wink>, it's to determine whether Python works  as expected.  If a
platform bug causes some test to fail, then that test _should_ fail on
that platform -- it's not a Python bug, after all, and users on that
platform aren't served by hiding that platform bugs cause Python tests
to fail.  If they try the same things in their programs they'll fail
there too, and the test suite is supposed to warn them about that.

If the primary goal here is really to "make the alpha Tru64 5.1
buildbot columns green", then maybe the Alpha needs a different test
runner, to exclude the tests that are doomed to fail due to Alpha
bugs.

> ...
> With gcc, there are also several issues:
>  * test_float and test_struct fail due to NaN handling
>  * test_long fails

Which version of gcc is in use?  Alpha hardware has incomplete support
for IEEE endcase semantics, and "it usually" requires a special
compiler option to generate code that hides the HW limitations.  That
you didn't list the above as failures using the native cc strongly
suggests that we're missing a necessary gcc Alpha trick.  You can go
to:

    http://gcc.gnu.org/onlinedocs/

pick the version of gcc, and drill down to the "DEC Alpha Options"
chapter for that version to see the Alpha tricks available.  Looks
like compiling with

    -mieee

would be an excellent idea for Python, and looks like we're not using
that now.  I've never used an Alpha, but I recall that this suggestion
fixed other peoples' problems :-)