[llvm] [AArch64] Create set.fpmr intrinsic and assembly lowering (PR #114248)

[via llvm-commits]

Lukacma wrote:

Hello David,

Thank you for your feedback! I have now fixed the first issue you had with the patch. As for the 2nd one, for now I don't think creating data dependencies is necessary. Functionally, dependencies between defs and uses of FPMR are going to be handled using memory dependency through inaccessible memory. I do not see a "nice" way to handle overlaping ranges  without using memory dependency, but if you know of a way I would be keen on hearing about it and we might change to data dependency only later. I agree that it will help with optimization to not have to search through the program for where the fpmr value might be coming from, but that is something we will think about once we start optimizing these intrinsics. 

https://github.com/llvm/llvm-project/pull/114248