* `st64 $aSrc0:Src0+1, $mBase0, $mDelta0, $mOffset0`
* `st64 $aSrc0:Src0+1, $mBase0, $mDelta0, zimm12`

Store a single 64-bit value, from a naturally aligned register pair
toTile Memory.

Source register-file: ARF only

Effective address formed from:

:   -   Base address (`$m` register)
    -   Unsigned address delta (`$m` register)
    -   Unsigned scaled offset (`$m` register or immediate)