On Thu, Feb 25, 2010 at 12:00 AM, Jason Merrill <ja...@redhat.com> wrote: > On 02/18/2010 07:46 PM, Joseph S. Myers wrote: >> >> On Thu, 18 Feb 2010, Jason Merrill wrote: >> >>> I periodically get bitten by bug 34115: a compiler configured without >>> --with-arch on i686-pc-linux-gnu doesn't support atomics. I think we >>> would >>> only need to bump the default to i486 to get atomic support. Can we >>> reconsider the default for 4.5? >> >> My position remains that configuring for i686-* should default to >> -march=i686 rather than -mtune=i686. >> >> http://gcc.gnu.org/ml/gcc/2008-06/msg00223.html >> http://gcc.gnu.org/ml/gcc/2008-08/msg00445.html >> >> Perhaps someone would like to review HJ's patch to that effect? >> >> http://gcc.gnu.org/ml/gcc-patches/2008-08/msg02078.html > > Perhaps one of the i386 maintainers?
The default arch should be based on what _users_ expect from the configure process, so it is IMO up to distributors and finally Release Managers to decide. As far as the proposed patch is concerned, I think that it is the step in the right direction, and is OK for 4.6, but also please also add -march=native choice. It works OK nowadays. Since this is build patch, it also needs OK from build maintainer (CCd). Uros.
