[Bug target/61058] [4.7/4.8/4.9/4.10 Regression] ICE: RTL check: expected elt 3 type 'B', have '0' (rtx barrier) in distance_agu_use_in_bb, at config/i386/i386.c:16740 with __builtin_unreachable()

[ubizjak at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61058

--- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> ---
Similar to PR54455, where Steven said:

--q--
There can't be a BARRIER in the middle of a basic block. This problem typically
indicates that either a BARRIER was emitted in the wrong place, or BB_END
wasn't updated properly after a BARRIER was inserted somewhere. BARRIERs never
appear inside a basic block.
--/q--

The target ICEs due to invalid BARRIER location, so it looks like
rtl-optimization bug to me.