[LLVMdev] Old-style code generators broken?

[Vladimir Prus]

Hi,
it looks like old-style code generators can no longer work with LLVM CVS,
because:

1. The TableGen uses the DAG from instruction to computed the number of
operands written in generated tables, and when there's no DAG, writes 0.

2. MachineInstructions::addRegOperand checks for maximum number of operands.

So, when not using DAGS in TableGen input, addRegOperand asserts on adding
the very first operand to any instruction.

If that was an explicit decision, maybe docs should be updated to say so?

- Volodya