[Bug middle-end/71514] ICE on C11 code with atomic exchange at -O1 and above on x86_64-linux-gnu: in copy_reference_ops_from_ref, at tree-ssa-sccvn.c:879

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71514

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Might have started with 
commit 6e1c78b5ec698f92f4f8e461630b3f7a6234697e
Author: jakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Sun Nov 6 19:43:32 2011 +0000

        * tree-cfg.c (gimple_can_merge_blocks_p): For -O0 don't remove
        any user labels.


    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181040
138bc75d-0d04-0410-961f-82ee72b054a4