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Re: Question on g++ compile options / numerical differences
- From: Alexandre Oliva <aoliva at redhat dot com>
- To: "Dockeen" <dockeen at mchsi dot com>
- Cc: <gcc at gcc dot gnu dot org>, <gcc-help at gcc dot gnu dot org>
- Date: 20 May 2002 07:47:43 -0300
- Subject: Re: Question on g++ compile options / numerical differences
- Organization: GCC Team, Red Hat
- References: <NCBBLKKJGBJOLDFMCKFPMEFJCAAA.dockeen@mchsi.com>
On May 19, 2002, "Dockeen" <dockeen@mchsi.com> wrote:
> Is there something transparently stupid in the additional
> options above that might lead to numerical calculations going
> bad?
Well, depending on the numerical stability of your code, -ffast-math's
effects may range from none to dramatic. Also, the possibility of one
of the other flags you're using being exposing a bug in GCC cannot be
ruled out, but it would require some work on your end to figure that
out and provide us with a testcase that demonstrates the problem.
--
Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer aoliva@{cygnus.com, redhat.com}
CS PhD student at IC-Unicamp oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist Professional serial bug killer