[Bug tree-optimization/44183] Vectorizer may generate invalid memory access

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44183

--- Comment #7 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-01-31 10:06:27 UTC ---
(In reply to comment #6)
> It depends on the specific values of (a) array end alignment and (b) the number
> of bytes read. As long as the array end + number of bytes read can cross a page
> boundary, you're potentially causing SEGV or other errors.

I don't think this can happen.  The access to the out-of-bounds area only
happens if there are pieces inluded in the last (aligned) vector move.
That vector move will be aligned so it can't cross page-boundary.  As
it contains at least one allocated element the access may not trap.