Bin Chen wrote: > 在 2007-10-16二的 09:23 +0200，Denis Oliver Kropp写道： >> Phil Endecott wrote: >>> I've also noticed that djpeg runs about 15% faster if compiled with -Os >>> rather than -O4. >> On x86? >> >> On embedded architectures, -O2 is often better than -O3, but if you have >> a very small instruction cache, -Os could be best. > > Its interesting, why -O2 is better?
O3 can produce code (loop unrolling etc.) where the cache penalty is bigger than the speed improvement. -- Best regards, Denis Oliver Kropp .------------------------------------------. | DirectFB - Hardware accelerated graphics | | http://www.directfb.org/ | "------------------------------------------" _______________________________________________ directfb-dev mailing list [email protected] http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-dev
