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[Bug fortran/29621] lapack runs into infinite loop with -03
- From: "sgk at troutmask dot apl dot washington dot edu" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 28 Oct 2006 02:59:33 -0000
- Subject: [Bug fortran/29621] lapack runs into infinite loop with -03
- References: <bug-29621-13059@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #15 from sgk at troutmask dot apl dot washington dot edu 2006-10-28 02:59 -------
Subject: Re: lapack runs into infinite loop with -03
On Sat, Oct 28, 2006 at 02:07:00AM -0000, fkar at nemesis-project dot org
wrote:
>
> > Are you building slamch.f and dlamch.f with -O3 or even -O1?
> > Don't. These files try to determine machine values (e.g.,
> > epsilon). Optimization can give some really strange answers.
>
> Thank you!!!
> That totally solved the problem and now the program executes fine.
>
> Is this a bug after all?
>
No. It is very old Fortran code that tries to
be clever. Unfortunately, aggressive optimization
will break the cleverness.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29621