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[Bug target/32180] Paranoia UCB GSL TestFloat libm tests fail - accuracy of recent gcc math poor
- From: "rob1weld at aol dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 15 Jun 2007 21:23:43 -0000
- Subject: [Bug target/32180] Paranoia UCB GSL TestFloat libm tests fail - accuracy of recent gcc math poor
- References: <bug-32180-13830@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #20 from rob1weld at aol dot com 2007-06-15 21:23 -------
Created an attachment (id=13709)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13709&action=view)
Specific example where libm, libcrlibm, and mpfr differ
Here is a specific example of three different math libraries providing three
different answers to the same question. The number does not use very many
decimal places and thus __could__ come up in common use.
It is not really how likely the number would be used that is important but what
the result of using the answer would be. If your life is important don't be it
on this number.
This is just one number. How many more could there be, how will you prove you
are correct and deduce the actual correct answer in those instances. This is
what you must answer. This is why we need a fast, simple, library that is
accurate and comes with "proof".
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32180