On Wednesday, January 05, 2011 8:36:06 am Dimitry Andric wrote: > On 2011-01-05 13:59, John Baldwin wrote: > >> Why not to add NO_HWFLOAT knob (or similar) into makefile > >> infrastructure. And set CFLAGS accordingly, depending on CC, arch, etc. > >> These flags are getting rather common in tree. > > > > It strikes me that we really want clang/gcc to have some sort of > > '-mno-hwfloat' so we don't keep having to add new flags in the future. > > This is not just about floats, clang can also use SSE/AVX instructions > for e.g. memset(), memcpy() and the like, or even for structure > assignments.
Yes, but the thing that all these extensions have in common is that they use FPU state (i.e. subject to DNA traps, managed via *SAVE and *RSTOR, etc.) and that is the problem with using them in boot code or rtld. What I would want a -mno-hwfloat flag to do is to disable use of anything that would require working FPU state handling. -- 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"
