[llvm] [LoongArch] Set isReMaterializable on LU{12,32,52}I.D/ADDI.D and {X}ORI instructions (PR #94552)

[via llvm-commits]

heiher wrote:

> Does this patch only touch LA32 tests? Is there any LA64 tests benefit from it?

Not only LA32, but also LA64 benefits. In a Rust benchmark case, an instruction that generates an operand for a conditional branch can be hoisted by LICM, depending on isTriviallyReMaterializable. (I can't reproduce it in a simple case :(

https://github.com/llvm/llvm-project/blob/ea32197daa8517ff67c0691ad24d25eb5cf905f4/llvm/lib/CodeGen/MachineLICM.cpp#L1212-L1215

https://github.com/llvm/llvm-project/pull/94552