Re: a.out binaries that are 66% faster than ELF

Bernd Schmidt (crux@Pool.Informatik.RWTH-Aachen.DE)
Wed, 26 Feb 1997 10:53:51 +0100 (MET)

> As some of you are probably aware, there are client programs
> that can be used in a cooperative effort to work on the RC5
> challenge. These are 100% CPU intensive, and I've found that
> an a.out binary compiled from the exact same source, same opt.
> flags, etc. is nearly 50% faster than the identical ELF version!
> I even tried linking the ELF binary static, but that didn't help.

Funny. A while ago there was a similar report on
I had planned to investigate but somehow didn't get around to it...

> I'd say that the performance difference between the ELF and a.out versions
> warrants an investigation of some sort. Comparing the "gcc -S" would be
> a good start I guess...

Those should be mostly identical, or something Very Wrong is going on.