[llvm-dev] question: access IR class Instruction from DAG SDValue

[Jonathan via llvm-dev]

The llvm backend uses class Instruction in IR handle stage, create SDVaule and DAG in DAG translation stage and class MachineInstr in Machine instruction translation stage.
Can I access class Instruction from DAG structure or stage, or access DAG and Instruction from MachineInstr structure or stage?

Jonathan