Function read_element_0_u64 

pub unsafe fn read_element_0_u64<const VLEN: Vlen>(
    vregs: &VectorRegisterFile<VLEN>,
    base_reg: VReg,
    sew: Vsew,
) -> u64

Read element 0 of register base_reg as u64, zero-extended.

Safety

sew.bytes() <= VLEN.bytes()