Messages in this thread | | | Date | Mon, 29 Sep 2008 11:17:34 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] x86: do not allow to optimize flag_is_changeable_p() |
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Krzysztof Helt wrote: > From: Krzysztof Helt <krzysztof.h1@wp.pl> > > The flag_is_changeable_p() is used by > has_cpuid_p() which can return different results > in the code sequence below: > > if (!have_cpuid_p()) > identify_cpu_without_cpuid(c); > > /* cyrix could have cpuid enabled via c_identify()*/ > if (!have_cpuid_p()) > return; > > Otherwise, the gcc 3.4.6 optimizes these two calls > into one which make the code not working correctly. > Cyrix cpus have the CPUID instruction enabled but > it is not detected due to the gcc optimization. > Thus the ARR registers (mtrr like) are not detected > on such a cpu. >
I suspect we should also out-of-line this function. It's actually relatively sizable and certainly there is no point in inlining it.
-hpa
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