LLVM ERROR: Don't know how to widen the operands for `INSERT_SUBVECTOR`

[abhishek-kaushik22]

define <8 x i32> @foo(<8 x i32> %a, <2 x i32> %b) {
  %result = tail call <8 x i32> @llvm.vector.insert.v8i32.v2i32(<8 x i32> %a, <2 x i32> %b, i64 0)
  ret <8 x i32> %result
}

https://godbolt.org/z/x6qnfPM7W

We get a fatal error in DAGTypeLegalizer::WidenVecOp_INSERT_SUBVECTOR for this seemingly simple code.
I'm not sure how this could be fixed. Can we just replace the INSERT_SUBVECTOR with a series of INSERT_VECTOR_ELT nodes?

There's also #102016 for AArch that also looks like the same problem as this one.

[llvmbot]

@llvm/issue-subscribers-backend-x86

Author: None (abhishek-kaushik22)

```llvm define <8 x i32> @foo(<8 x i32> %a, <2 x i32> %b) { %result = tail call <8 x i32> @llvm.vector.insert.v8i32.v2i32(<8 x i32> %a, <2 x i32> %b, i64 0) ret <8 x i32> %result } ```

https://godbolt.org/z/x6qnfPM7W

We get a fatal error in DAGTypeLegalizer::WidenVecOp_INSERT_SUBVECTOR for this seemingly simple code.
I'm not sure how this could be fixed. Can we just replace the INSERT_SUBVECTOR with a series of INSERT_VECTOR_ELT nodes?

There's also #102016 for AArch that also looks like the same problem as this one.