[llvm] [TableGen] Support for optional chain in Selection DAG nodes (PR #163079)

[Craig Topper via llvm-commits]

topperc wrote:

Did you consider making FP nodes always have a chain and using EntryNode as the chain input for non-strict FP opcodes? You could use a bit from SDNodeBitfields, which I think is unused for arithmetic nodes to indicate the node is strict. This would give a consistent operand order.

https://github.com/llvm/llvm-project/pull/163079