On Thursday 18 March 2010 9:16:53 pm Xin LI wrote: > Author: delphij > Date: Fri Mar 19 01:16:53 2010 > New Revision: 205307 > URL: http://svn.freebsd.org/changeset/base/205307 > > Log: > SSE is enabled by default about 5 years ago so there is no point pretending > that we support I486 and I586 CPUs in the GENERIC kernel, users wants these > support would have to build a custom kernel to explicitly disable SSE > anyways. > > MFC after: 1 month
No, this is wrong. Revert this. We do _not_ unconditionally use SSE in the kernel. GENERIC should run just fine on a 486. If it doesn't, that should be fixed, but I have not seen any reports to the contrary. In general we do not use any floating-point / MMX / SSE instructions in the kernel as our FPU context-saving code doesn't support it. All the x86 world is not rack-mounted 64-bit servers. We should not remove support for non-686 CPUs for no good reason. 486 CPUs have cmpxchg and xadd so are perfectly adequate. -- John Baldwin _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
