[Bug target/62642] [4.8/4.9/5 Regression] x86 rdtsc is moved through barrier

[vmakarov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62642

--- Comment #3 from Vladimir Makarov <vmakarov at gcc dot gnu.org> ---
The problem is in a live range splitting optimization to reduce register
pressure.  It was introduced by

https://gcc.gnu.org/ml/gcc-patches/2011-12/msg01531.html

It is easy to switch off for this kind of insns.  I'll submit the patch on
Monday.