[llvm] [RISCV] Enable rematerialization for scalar loads (PR #166774)

[Craig Topper via llvm-commits]

topperc wrote:

> Craig, can you expand on the later just a bit? As long as we don't move the AUIPC, isn't the low offset fixed? It's the pc relative offset from the AUIPC to the global, not from the LD to the global isn't it?

You're right. Remating the load should be fine. It has a reference to a symbol on the auipc. We can remat that since we can have multiple instructions referring to the same auipc. It's auipc that we can't rematerialize since that would need a new symbol.

https://github.com/llvm/llvm-project/pull/166774