------- Comment #1 from changpeng dot fang at amd dot com 2010-07-21 18:26 ------- The direct reason is that prefetching could not differentiate the base addresses of the vectorized load and store (of a[i]): *vect_pa.6_24 *vect_pa.19_37
-- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45021