[Bug tree-optimization/57417] [4.7/4.8/4.9 Regression] hang on volatile int array

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57417

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 30202
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30202&action=edit
prototype patch

Like the attached.