On Wed, 2011-11-23 at 14:08 +0000, Ian Campbell wrote: > > The Intel manuals[0] suggest (in section 13.5 "DETECTION OF AVX > INSTRUCTIONS") that the appropriate sequence to use from userspace to > detect AVX is: > 1. Detect CPUID.1:ECX.OSXSAVE[bit 27] = 1 (XGETBV enabled for > application use1) > 2. Issue XGETBV and verify that XCR0[2:1] = ‘11b’ (XMM state and > YMM state are enabled by OS). > 3. detect CPUID.1:ECX.AVX[bit 28] = 1 (AVX instructions > supported). > > glibc currently only does #3. > > If I am right then using "noxsave" on native should demonstrate the > issue as well and show that there is a bug in libc.
Which seems to already be reported and fixed upstream: http://sourceware.org/bugzilla/show_bug.cgi?id=13007 as well as against glibc in Debian http://bugs.debian.org/646549. The fix is fixed in glibc-package SVN so ought to be fixed with the next upload (2.13-22). Cheers, Ian. -- Ian Campbell Current Noise: Callenish Circle - My Hate Unfolds Of course you have a purpose -- to find a purpose. -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
