[Bug c/47409] volatile struct member bug

[regehr at cs dot utah.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47409

--- Comment #12 from John Regehr <regehr at cs dot utah.edu> 2013-01-30 23:24:36 UTC ---
(In reply to comment #10)
> As said previously I think that volatile struct members are ill-defined.

As far as the C standard goes, I believe the situation is clear: a volatile
struct member is a volatile-qualified variable and the rules for volatile
variables apply to it.

Clang, for example, turns foo() into a load + store at all optimization levels.
I believe the Intel compiler does as well but I don't have it available right
now.