best options for gcc under athlon64

exodist · 12-16-2004, 05:14 PM

I am a gentoo user and will soon have an athlon64, I am wondering what would be the best gcc flags to use for best performance of compiled software.

I am guessing march=athlon64, but what others would be good?

rjlee · 12-17-2004, 05:20 AM

-O3 will turn on heavy optimization, optimizing your code for speed.

You can fine-tune this optimizations using the various -fflag switches instead. Unfortunately, the actual effect on a program's performance depends largely on how the program was written, so there's no right answer except to use trial and error and monitor the effect of each option on performance using a tool like gprof.

Electro · 12-17-2004, 03:21 PM

Go to the gnu web site look through the gcc documentation. Like what rjlee said each program is different, so trial and error is the best thing.