[PATCH] D151449: [RISCV] Add DAG combine for CTTZ/CTLZ in the case of input 0

[Alex Bradbury via Phabricator via llvm-commits]

asb added a comment.

I forgot to also say that it's best to strip attributes that don't influence codegen. In this test case, `noundef`, `nocapture` and `readonly` don't alter the output if removed, so best to just get rid of them.


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  https://reviews.llvm.org/D151449/new/

https://reviews.llvm.org/D151449