[llvm] [ExpandMemCmp] Recognize canonical form of (icmp sle/sge X, 0) in getMemCmpOneBlock. (PR #121540)

[Craig Topper via llvm-commits]

topperc wrote:

> We seem to have UCMP and SCMP SelectionDAG nodes, are these cases simply missing generic DAG combines? No objection to this patch, just wondering about possible followup.

They are missing. It was mentioned in the description originally as a question about whether to do this here or in DAGCombine. I removed it when I committed based on Nikita's comment https://github.com/llvm/llvm-project/pull/121540#pullrequestreview-2528778988

https://github.com/llvm/llvm-project/pull/121540