[gentoo-user] Re: Flash and cpu_flags_x86_sse2

[James]

Mike Gilbert <floppym <at> gentoo.org> writes:


> > CPU_FLAGS_X86="mmx sse sse2 sse3 ssse3 sse4 sse4_1 sse4_2 sse4a ssse3 \
> > mmx mmxext xop 3dnowprefetch  3dnow 3dnowext aes avx  avx2 fma3 fma4 \
> > padlock popcnt "

> Exactly how did you "surmise" your list?

cat /usr/portage/profiles/desc/cpu_flags_x86.desc

which is a subset of the CPU flags found in /proc/cpuinfo


> > What would be cool, is if the devs took the entire list of cpu flags
> > from proc/cpuinfo and piped it thru a simple validation script (equery
> > hasuse) to generate the maximum flags to set by default for a given cpu.
> That's exactly what cpuinfo2cpuflags-x86 does.

So the list given by the current script does not include all of the
flags listed in //usr/portage/profiles/desc/cpu_flags_x86.desc


That's the explanation I was looking for. The only thing I can think
of is the extra flags are not every used in current packages found
in the portage tree. I wonder if gcc(++) might could make use
of those flags. I'm not making a statement, but framing a question.

But I would think that is the reason for the subset of /proc/cpuinfo
that forms the flags listed in :
/usr/portage/profiles/desc/cpu_flags_x86.desc

hth,
James