[llvm] [RISCV][RFC] Add additional opcodes to RISCVDAGToDAGISel::hasAllNBitUsers (PR #147728)

[Craig Topper via llvm-commits]

topperc wrote:

> If there should be any particular threshold for adding things to the ISel hasAllNBitUsers or we should just keep it in sync best effort (as this PR tries to do)

My primary concern is the compile time cost of the recursion. If we can't construct a test case that shows benefit then I'm not sure we should pay that cost.

https://github.com/llvm/llvm-project/pull/147728