LLVM Retargeting Tutorial : Building a backend in 24 hours (2009) Tutorial : Building a backend in 24 hours (2012) Understanding SelectionDAG construction CodeGen Overview and Focus on SelectionDAGs Design and Implementation of a TriCore Backend for the LLVM Compiler Framework Resources LLVM Developers' Meeting Useful Post in llvm-dev list [LLVMdev] Data layout and Optimization [LLVMdev] CodeGen instructions and patterns [LLVMdev] Pattern matching in a SelectionDAG [LLVMdev] Conceptual difference between "Unallocatable" and "Reserved" registers. [LLVMdev] The meaning of SDNPHasChain Libraries. STLPort: A port of the original STL to many platforms. Derived from the SGI implementation. Memo llvm/lib/Target/ISDOpcodes.h. The target-independent operators for a SelectionDAG are defined here. llvm/include/llvm/CodeGen/SelectionDAGNodes.h. SDNode class and derived classes are defined here.