[llvm] [AArch64] Replace AND with LSL#2 for LDR target (#34101) (PR #89531)

[David Green via llvm-commits]

davemgreen wrote:

Hi. There is code in the DAG combiner to attempt to stop reassociations that would break the addressing mode.
https://github.com/llvm/llvm-project/blob/654846560c8892b32ea1e92c1fffc5e70bf0e75f/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp#L2690
I've not looked into this case in a lot of details, there is a chance the transform happens in a few different places, but could the same thing be done here?

https://github.com/llvm/llvm-project/pull/89531