Messages in this thread |  | | From | "H. Peter Anvin" <> | Subject | Re: missing mxcsr initialization | Date | 25 Oct 2000 18:11:54 -0700 |
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Followup to: <39F77A0F.BA1422C9@redhat.com> By author: Doug Ledford <dledford@redhat.com> In newsgroup: linux.dev.kernel > > On that specific bit I haven't seen it go out of sync yet. However, I program > it defensively because I already got bit by the fact that the X86_FEATURE_PN > bit on Intel means something different than on AMD and as a result of getting > it wrong my first time out, AMD CPUs were segfaulting when I tried to disable > their non-existent serial number. So, since these bits vary from vendor to > vendor, I would prefer to see it handled like the PN bit, that is check for > all vendors that *do* use the bit to mean FXSR or XMM, but don't rely on all > vendors to do so. In that case, we could check for vendor == INTEL || vendor > == AMD, but I would still prefer to see *some* check on the vendor before > honoring the bits. >
This isn't defensive programming at all. You *introduce* bugs this way; instead of handling (CPU) bugs as the workarounds they are.
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