[Bug tree-optimization/47391] [4.5/4.6 Regression] read from const volatile incorrectly eliminated

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47391

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-01-21 
08:36:08 UTC ---
Created attachment 23058
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23058
gcc46-pr47391.patch

Untested fix.