http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59569
--- Comment #9 from Bingfeng Mei <bmei at broadcom dot com> --- Seems simple patch is to just bypass permutation for constant operand as vec_oprnd is a constant vector with identical elements. Index: tree-vect-stmts.c =================================================================== --- tree-vect-stmts.c (revision 206176) +++ tree-vect-stmts.c (working copy) @@ -5353,7 +5353,8 @@ vectorizable_store (gimple stmt, gimple_ set_ptr_info_alignment (get_ptr_info (dataref_ptr), align, misalign); - if (negative) + if (negative + && !CONSTANT_CLASS_P (gimple_assign_rhs1 (stmt))) { tree perm_mask = perm_mask_for_reverse (vectype); tree perm_dest