This may be a silly point to bring up, but it hasn't been mentioned whether the code was compiled with optimizations, and what level. My understanding is that -march only specifies which instructions are allowed to be emitted by the compiler. You can compile with -march=native -O0 and still have slow code. Brian On Thu, May 7, 2009 at 10:59 AM, Tim Prince <TimothyPrince@xxxxxxxxxxxxx> wrote: > John (Eljay) Love-Jensen wrote: >>> >>> You mean -mcpu= . >>> >> >> I thought -mcpu was a deprecated synonym for -mtune. >> >> Whereas -march implies -mtune, but is not a synonym for -mtune. >> >> My understanding may be out of date. >> >> > > I wouldn't have much hope for gcc if an understanding more up to date than > Eljay's were needed. >
