A little while ago I posted about the non-implementation
of the AMD 64 SSE 4.2 instructions PCMPxSTRx for 16-bit
characters (many 8-bit sub-operations were supported).
I got them working, and was (reasonably) directed to
move to svn head if I want to be able to send in a
patch.

I did that, but when I run the updated valgrind on
the same program as before (Oracle's HotSpot JVM),
it fails on a 0xF 0xAE 0x3F instruction, which
appears to be either a CLFLUSH or an SFENCE (both
decode the same way in the docs, so I am slightly
confused).  Either way, it worked in the latest
stable release, and I didn't mess with that decoding.

I will see if I can replicate it on svn head without
my mods, but wanted to give a heads up. Any notion
what's happening?

It is becoming apparent that it might be nice to
have more control over which x86 family processor
is supported as the guest. If I downgraded the guest
some then I think that HotSpot would avoid these
instruction that I am having to add ... which come
about apparently because valgrind claims via cpuid
to support a really advanced processor, but then does
not support all of its instructions.  But I can see
that it would be a significant project to support
a range of guest processor capabilities controlled
with flags, etc.

Regards -- Eliot Moss

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