We aren't going to connect the result to anything so we might
as well avoid allocating a register.
Reviewed By: frasercrmck, HsiangKai
Differential Revision: https://reviews.llvm.org/D102031
In vector v0.10, there are whole vector register load/store
instructions. I suggest to use the whole register load/store
instructions for generic load/store for scalable vector types. It could
save up vset{i}vl{i} for these load/store.
For fractional LMUL, I keep to use vle{eew}.v/vse{eew}.v instructions to
load/store partial vector registers.
Differential Revision: https://reviews.llvm.org/D95853
Craig Topper