Bug with g77 and -mieee on Alpha Linux

[Martin Kahlert]

Quoting Toon Moene (toon@moene.indiv.nluug.nl):
> Martin Kahlert wrote:
> > 
> > Quoting craig@jcb-sc.com (craig@jcb-sc.com):
> 
> > > My own opinion is that this sort of thing is insanely painful to deal with,
> > > and that the default should have been -mieee all along (both for gcc and
> > > for Digital's compilers, but I assume the latter have all-along offered
> > > easier ways to get the -mieee behavior), with an option (-mno-ieee) being
> > > needed to get -mno-ieee performance.
> > I have to agree heavily on that.
> 
> I'm sorry, but I am going to respectfully disagree.  Full IEEE
> comformance is very expensive on the Alpha's and the reason you need it
> very uncommon.  Martin provoked it by passing a denormal to libg2c, but
> *in normal programming* running into denormal should point to some error
> in the logic of your algorithms.

> [ Unless you're in cosmology and try to express everything in 32-bit
>   REALs using SI units - my point is that nobody *does* that. ]

Perhaps, but while solving highly nonlinear sets of equations, like in
analog circuit simulators nearly anything can appear. Nobody knows,
where newton will bring you. You can decide to make smaller newton corrections
only  a f t e r  you have the bad ones and thus you have to deal with these
bad numbers somehow.

But anyway, egcs-2.95 (19990629-snapshot) seems to have a problem in
its optimizer on Alphas, since these problems disappear when i compile
without optimization - strange,  but it's very hard even to tell which
file was compiled wrongly. Perhaps i can find anything useful.

Thanks for your reply,
Martin.

-- 
esa$ gcc -Wall -o ariane5 ariane5.c
ariane5.c: 666: warning: long float implicitly truncated to unsigned type
esa$ ariane5