On Mon, 09 Jun 2008 06:43:41 +0100 Graham Murray <[EMAIL PROTECTED]> wrote:
> Andrew Gaydenko <[EMAIL PROTECTED]> writes: > > > gcc-4.3.1 is umasked now. I'm on ~amd64 with Core 2 Duo CPU. Is it > > sufficient just to set > > > > CFLAGS="-O2 -march=core2 -mtune=core2 -pipe" > > > > instead of > > > > CFLAGS="-O2 -march=native -mtune=native -pipe" > > > > which I have in make.conf now? Are there any other things to do? > > Should the two not be equivalent? On a core2 processor, should > -march=native not generate code for the core2? If we are going to get picky about this, it should be noted the -march implies -mtune, at least according to the gcc man pages, and I will trust them to know. I can't remember which will actually be implemented if both are specified, but march is a essentially a stronger version of mtune which breaks compatibility with other CPUs within the same ARCH type. (i.e. march=pentium4 may not run on a pentium3, but should run faster than mtune on a pentium4) RobbieAB -- [email protected] mailing list
