https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69368
--- Comment #10 from alalaw01 at gcc dot gnu.org --- The stores are getting optimized out because equal_mem_array_ref_p considers equal pairs of MEM_REFS like fmcom.x[_168] and fmcom.x[_208] That is, a ARRAY_REF whose first operand is a COMPONENT_REF fmcom.x (of a VAR_DECL and a FIELD_DECL), and whose second operand is an SSA_NAME _168 or _208; I don't see anything obvious to suggest that they should be equal). get_ref_base_and_extent then returns base=fmcom, size=64, max_size=64 (so not a variable-sized access), and offset 0 :-(.
