[Bug tree-optimization/53085] writes to volatile struct members is missing

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53085

--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-24 
13:13:26 UTC ---
Patch that applies to all maintained branches (the bug is also in 4.5!)

Index: gcc/tree-ssa-pre.c
===================================================================
--- gcc/tree-ssa-pre.c  (revision 186760)
+++ gcc/tree-ssa-pre.c  (working copy)
@@ -4409,6 +4409,7 @@ eliminate (void)
             has the same value number as its rhs.  If so, the store is
             dead.  */
          else if (gimple_assign_single_p (stmt)
+                  && !gimple_has_volatile_ops (stmt)
                   && !is_gimple_reg (gimple_assign_lhs (stmt))
                   && (TREE_CODE (rhs) == SSA_NAME
                       || is_gimple_min_invariant (rhs)))