LO_VEC
__asm("stvx %2,%1,%0" :: "b"(vp), "r"( 0), "n"(LO_VEC));
[lv] "n"(LO_VEC), [hv] "n"(HI_VEC));
__asm("lvx %2,%1,%0" :: "b"(vp), "r"( 0), "n"(LO_VEC));