[llvm] [GISEL] Add G_SPLAT_VECTOR_PARTS to represent 64-bit splat vectors on… (PR #86970)

[Michael Maitland via llvm-commits]

michaelmaitland wrote:

> Which is the "lower level" representation? SPLAT_VECTOR_PARTS or a SPLAT of G_MERGE? Can we lower SPLAT_VECTOR_PARTS to the merge representation for targets that don't need it?

I think targets that don't need it can lower to the merge representation. I think it depends on your target which is the lower level representation.

> I'm also wondering if since only RISCV seems to need this whether we can just make it a RISCV G_ opcode.

I am okay with this. This way we don't need to worry about other targets needing to lower it.


https://github.com/llvm/llvm-project/pull/86970