backing registers, so SETVL has the maxVL as an immediate value. There is no
maxVL CSR needed for just SVPrefix.
+> when looking at a loop assembly sequence
+> i think you'll find this approach will not work.
+> RVV loops on which SV loops are directly based needs understanding
+> of the use of MIN. Yes MVL is known at compile time
+> however unless MVL is communicates to the hardware, SETVL just
+> does not work.
+> The only other option which does work is to set a mandatory
+> hardcoded MVL baked into the actual hardware.
+> That results in loss of flexibility and defeats the purpose of SV.
+
--
With SUBVL (sub vector len) being both a CSR and also part of the 48/64