------- Comment #3 from rguenth at gcc dot gnu dot org 2010-07-04 13:27 ------- I can see on current trunk when dumping rtl-expand-alias that some of the pointers created by the vectorizer miss alias information, namely those in the loop pre-header:
<bb 7>: base_off.26_73 = prolog_loop_niters.16_27 * 2; vect_p.27_74 = b_9(D) + base_off.26_73; vect_p.24_75 = vect_p.27_74; base_off.31_79 = prolog_loop_niters.16_27 * 2; vect_p.32_80 = a_5(D) + base_off.31_79; vect_p.29_81 = vect_p.32_80; that, together with IVOPTs loosing points-to information for PHI node replacements may the the issue here. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44479
