On Fri, Oct 05, 2007 at 08:15:09AM -0600, Jeremy Huntwork wrote: > On Fri, 05 Oct 2007 09:10:59 -0500, Bruce Dubbs <[EMAIL PROTECTED]> wrote: > > Both your links are the same... > > Oh, sorry. Here's the one I left out: > > http://linuxfromscratch.org/pipermail/lfs-dev/2007-September/060268.html
For the record, I agree with Greg's comments in that link (although I don't do much experimentation with the toolchain, so take that with a grain of salt). I'd say that CFLAGS is probably the right place to add this setting. (That's just based on Greg's comments about how glibc doesn't use CFLAGS for .S files.) As far as -mtune goes, I don't think that having a too-high -mtune value can cause a bug (even Alexander's conservative settings on the livecd build use -mtune=i686), so I don't see any problem with adding -mtune to the book. I'd also say that "native" is the right value to use, simply because we don't know exactly what CPU the various users will be building for. As for the comments in section 6.1, I'd almost recommend removing -mtune and leaving it that way. But that still doesn't quite work well. Maybe something like: Using a non-default optimization level on the toolchain packages (binutils/gcc/glibc) may cause problems. The flags used for these packages in the book have been tested to provide a stable and reasonably fast system. Using any other optimization flags for these three packages is not recommended. (Or something like that: the points I'm trying to get across are that (1) the -march flag is required, (2) the -mtune flag doesn't cause any other grief, and (3) -mtune=i486 would be really slow. And that we don't do anything with binutils or gcc because they shouldn't have anything done to them.)
pgpFgpwI7UEGb.pgp
Description: PGP signature
-- http://linuxfromscratch.org/mailman/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
