#include "llvm/CodeGen/SelectionDAG.h" SelectionDAG dag; // Create a DAG node for the constant 42 SDValue constNode = dag.getConstant(42, MVT::i32); // Create a DAG node for the register $eax SDValue eaxNode = dag.getRegister(XXX, MVT::i32); // Insert a copy from $eax to $ebx SDValue copyNode = dag.getCopyToReg(ebx, XXX, eaxNode, constNode);In this example, XXX is the identifier of the machine register class that contains the registers $eax and $ebx. The DAG node returned by getCopyToReg represents the copy operation and can be inserted into the DAG using the appropriate DAG mutation method. The SelectionDAG getCopyToReg method is part of the LLVMCodeGen library package.