compiler performance

[Richard Guenther]

Dara Hazeghi wrote:
> 
> "C: compiled with gcc -march=pentium4 -msse2
> -mfpmath=sse -O3 -s -mno-cygwin to optimize for my
> CPU, enable SSE2 extensions for as many math
> operations as possible, and link to Windows libraries
> instead of Cygwin libraries."
> 
> Doubtless it would look even worse were they to use
> Intel's compiler...

With gcc 3.3.1 they shouldn't have used -mfpmath=sse and for sure
enabled -ffast-math, as probably all other compilers default to
optimize for speed rather than correctness.  Also adding -funroll-loops
and -fomit-frame-pointer would probably help, we don't enable these even 
at -O3...

Richard.