https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81022
--- Comment #2 from Kirill Yukhin <kyukhin at gcc dot gnu.org> --- Intrinsics guide states [1] that this intrinsic: Store the lower double-precision (64-bit) floating-point element from a into memory. mem_addr does not need to be aligned on any particular boundary. [1] - https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_mm_store_sd&expand=5157