[llvm] [RISCV] Prefer alt opcode vectorirazion if unaligned vector mem accesses (PR #154153)

[Mikhail Gudim via llvm-commits]

mgudim wrote:

> Tests

@alexey-bataev I am actually struggling to come up with a simple test where split vectorization would trigger. Can you please point me to an example.

https://github.com/llvm/llvm-project/pull/154153