[llvm] [GISel] Explicitly disable BF16 tablegen patterns. (PR #124113)

[David Green via llvm-commits]

davemgreen wrote:

> Do we have a tracking issue for bf16? Should mention to revert this there

I couldn't see one for BF16 specifically, but I'll add a note to #115133 and FYI @tgymnich if you run into this. Hopefully it is fairly obvious that none of the patterns are importing or types work when we can use bf16 correctly. Let me know if you know of a better place, quite a lot has changed now..

Sorry - This is running into other issues, where the opposite happens for certain intrinsics and instructions with fp16 types are using bf16 patterns. As in https://godbolt.org/z/1KcvszrY7.  I have applied the fairly heavy hammer of forcing all IR with bf16 types to fall back to SDAG. This shouldn't be a problem for data-processing only instructions (load, stores, call params, shuffles, inserts, extract, select, etc there are a lot of them), but they are currently included to make sure everything is covered properly.

https://github.com/llvm/llvm-project/pull/124113