[llvm] [DAG][X86] Improve custom i256/i512 AVX512 CTLZ/CTTZ Handling with MVT::i256/i512 (PR #168860)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

> Is there any other work to do when adding new simple types? I see we can expand up to i128 libraries for now, do we need to extend it to i512?

Not that I've found so far - but the nvptx regression hints that there might be other code that does a isSimple() test - but its hasn't bit us yet. I'll double check the libcall situation

https://github.com/llvm/llvm-project/pull/168860