https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111970
--- Comment #17 from Richard Biener <rguenth at gcc dot gnu.org> --- OK, so for RISC-V with the testcase from the description there's the following issue: _179 = &MEM <vector(64) unsigned char> [(uint8_t *)_618]; _225 = BIT_FIELD_REF <MEM <vector(64) unsigned char> [(uint8_t *)_179], 8, 16>; ... vect__8.9_405 = {_218, _224, _230, _236, _242, _248, _254, _260, _266, _272, _278, _284, _290, _296, _302, _308, _314, _320, _326, _332, _338, _344, _350, _356, _362, _368, _374, _380, _386, _392, _398, _404}; vect__11.11_599 = vect__8.9_405 + { 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0, 1.0e+0, 2.0e+0 }; _609 = (void *) ivtmp.31_622; MEM <vector(32) float> [(float *)_609] = vect__11.11_599; _1 = _609 + 128; MEM <vector(32) float> [(float *)_1] = vect__11.11_599; I think the following fixes it: diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc index 96e4a6cffad..bf8c99779ae 100644 --- a/gcc/tree-vect-stmts.cc +++ b/gcc/tree-vect-stmts.cc @@ -9188,7 +9188,8 @@ vectorizable_store (vec_info *vinfo, unsigned HOST_WIDE_INT factor = const_offset_nunits / const_nunits; vec_offset = vec_offsets[(vec_num * j + i) / factor]; - unsigned elt_offset = (j % factor) * const_nunits; + unsigned elt_offset + = ((vec_num * j + i) % factor) * const_nunits; tree idx_type = TREE_TYPE (TREE_TYPE (vec_offset)); tree scale = size_int (gs_info.scale); align = get_object_alignment (DR_REF (first_dr_info->dr)); @@ -11150,7 +11151,8 @@ vectorizable_load (vec_info *vinfo, unsigned HOST_WIDE_INT factor = const_offset_nunits / const_nunits; vec_offset = vec_offsets[(vec_num * j + i) / factor]; - unsigned elt_offset = (j % factor) * const_nunits; + unsigned elt_offset + = ((vec_num * j + i) % factor) * const_nunits; tree idx_type = TREE_TYPE (TREE_TYPE (vec_offset)); tree scale = size_int (gs_info.scale); align = get_object_alignment (DR_REF (first_dr_info->dr));