* MVL (the Maximum Vector Length)
* VL (which has different characteristics from standard SPRs)
-* SUBVL (effectively a kind of SIMD)
+* SUBVL (effectively a kind of Packed SIMD of size 2, 3 or 4)
* SVSTATE (containing copies of MVL, VL and SUBVL as well as context information)
* SVSRR0 which is used for exceptions and traps to store SVSTATE.