[Discuss] Test for positive gives wacko results for underflowed values for the gcc compiler suite (including the gcc compiler, and g77 and gfortran compilers)

[Alan W. Irwin]

On 2007-06-25 16:14-0700 David Bronaugh wrote:

> Have you searched the GCC bug database? It might be a good idea at this 
> point.

Hi David:

I just now tried a search for "underflow" at
http://gcc.gnu.org/bugzilla/query.cgi and got 8 hits, but none of them seem
relevant.

Normally, I have the confidence to make bug reports, but I must say in this
case I am somewhat intimidated since they already have a case about
floating-point representations issues (see 
http://gcc.gnu.org/bugs.html#nonbugs_general), my gcc compiler is pretty out
of date (I don't have the latest Ubuntu), and besides that I know very
little about compilers.

David, if you confirm the result for my latest simple C example on your
latest/greatest gcc and think it really must be a gcc bug, do you have the
confidence/knowledge to report the problem yourself?

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of
Linux Links project (loll.sf.net); and the Linux Brochure Project
(lbproject.sf.net).
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