[Bug middle-end/57649] [4.7 Regression] ICE in set_is_used

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57649

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #5)
> Isn't it going to cause problems if we fold some accesses to the static var
> using the expressions in the initializer, we'd end up with not having the
> vars referenced?

Well - we are carefully trying to add them at the point we fold ...

> If backporting anything, my preference would be to actually backport just
> the tree-ssa-live.c change and not the tree-dfa.c change.
> Or Eric's patch.

Backporting just the tree-ssa-live.c change also works for me.