[llvm] [RISCV][GISel] Add initial support for rvv intrinsics (PR #156415)

[Craig Topper via llvm-commits]

topperc wrote:

> Another pr would be created for regbankselect pass to make vf form intriniscs have the right scalar register bank.

What about i64 scalar operands on RV32?

https://github.com/llvm/llvm-project/pull/156415