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Re: real.c fails floating point tests
- From: dewar at gnat dot com (Robert Dewar)
- To: gdr at integrable-solutions dot net, steve at moshier dot net
- Cc: gcc at gcc dot gnu dot org
- Date: Wed, 16 Oct 2002 11:05:59 -0400 (EDT)
- Subject: Re: real.c fails floating point tests
> That is too harsh and unfair to be a basis of a productive technical
> discussion.
Well I must say that I am surprised that anyone would install an IEEE
arithmetic simulator without running paranoia, this seems an absolutely
essential first step in testing any such software. I don't see it as
unfair at all to point out that this was a real misstep.
Certainly for GNAT, we will reinstall the old version until this is
fixed, since this seems like a very serious source of problems given
that in Ada absolute accuracy of arithmetic is required.
One thing to learn from this is that paranoia should be a standard part
of the testing process for GCC. So that should be put on the list of
desirable projects.
It is one thing to say that you don't expect things to be 100% perfect,
but this degree of failure in paranoia is really not acceptable at all
I think.
Anyway, the question is what is the right step forward now, can we fix
the current code relatively quickly (a caution is that any such code
is very delicate, and it may not be easy to fix), or would it be better
to reinstall the old simulator pending this being done.
This is definitely a very serious breakage from where I sit (it could
explain a number of failures we have been seeing in GNAT 5).
I realy appreciate Stephen's work here, and really I don't think I
would call his message a flame, just reasonable technical concern over
a serious problem :-)
Stephen, how easy would it be to install the paranoia test in an easily
reusable form, so that this test can be run periodically?