Kerstin Hoef-Emden schrieb:
> So you are recommending either to use only -mcpu= or to use both with
> -mcpu= first?
Both. -mcpu=ev56 instructs the compiler to generate code specifically
for ev56 CPUs and -Wa,-m21164a instructs the assembler to accept it.
> What are the "symptoms" that a special code needs -mieee? Most packages
> which I compile, are used for molecular phylogeny. MrBayes, as the name
> says, works with Bayesian methods. I guess, that fpu-operations are
> heavily used in these kind of calculations.
Crashes at runtime. AFAIK the whole problem is that Alpha CPUs can't
handle denormals. Using -mieee the compiler adds support for denormals
in software, which costs performance. So use this option only if you
need it, specifically only for those modules which need it.