------- Comment #2 from sebastian dot huber at embedded-brains dot de 2010-09-10 15:43 ------- (In reply to comment #1) > >1. index is constant or variable, and > > Yes that is correct. > > >2. the 'bar' field type. > > The alignment of the access is different in those cases.
Sorry, the test case was not good. If you expand foo [1] to foo [4] you still have this behavior. > > >In any case byte accesses should be used. > Why, word access is just as fast (if not faster) than a byte access on PPC. > Yes, but we have 'volatile struct type1 *varN;'. For volatile fields we should use accesses of the appropriate width. The background is that a major hardware manufacturer provided structure definitions like the above test case for register definitions. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45637
