[llvm] [RISCV][ISel] Fold trunc (lshr (add (zext X), (zext Y)), 1) -> vaaddu X, Y (PR #76550)

[Luke Lau via llvm-commits]

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lukel97 wrote:

Could we rename this to `vaaddu-sdnode.ll` to match the other tests? I believe we usually use `vfoo.ll` for intrinsic tests and `vfoo-sdnode.ll` for tests on generic SD nodes. 

We also typically just use scalable vectors since they're the "native" vector type. Fixed vector tests then go into `fixed-vectors-vfoo.ll`.



https://github.com/llvm/llvm-project/pull/76550