LLVM

• LLVM Documents
  1. LLVM Doxygen
  2. LLVM Programmers Manual
  3. LLVM Language Reference Manual
  4. LLVM Target-Independent Code Generator
  5. Writing an LLVM Compiler Backend
  6. TableGen Fundamentals

• Retargeting

  1. Tutorial : Building a backend in 24 hours (2009)
  2. Tutorial : Building a backend in 24 hours (2012)
  3. CodeGen Overview and Focus on SelectionDAGs
  4. Design and Implementation of a TriCore Backend for the LLVM Compiler Framework

• Resources

  1. LLVM Developers' Meeting

• Useful Post in llvm-dev list

  1. [LLVMdev] Understanding SelectionDAG construction
  2. [LLVMdev] Data layout and Optimization
  3. [LLVMdev] CodeGen instructions and patterns
  4. [LLVMdev] Pattern matching in a SelectionDAG
  5. [LLVMdev] Conceptual difference between "Unallocatable" and "Reserved" registers.
  6. [LLVMdev] The meaning of SDNPHasChain
  7. [LLVMdev] Question about 'side-effect' and 'chain'
  8. [LLVMdev] Difference between pattern and dag2dag isels
  9. [LLVMdev] Question about porting LLVM - code selection without assembler feature
  10. [LLVMdev] Where can I find an explanation of $src1, $src2, $in, $ptr, etc.?
  11. [LLVMdev] Adding a custom calling convention
  12. [LLVMdev] LLVM new backend compiling/linking problem
  13. [LLVMdev] Meaning of MIOperandInfo
  14. [LLVMdev] predicates and conditional execution

• Libraries.

  1. STLPort: A port of the original STL to many platforms. Derived from the SGI implementation.
  2. Microsoft Predefined Macros

• Memo

  1. llvm/lib/Target/ISDOpcodes.h. The target-independent operators for a SelectionDAG are defined here.
  2. llvm/include/llvm/CodeGen/SelectionDAGNodes.h. SDNode class and derived classes are defined here.
  3. TokenFactor Node This node takes multiple tokens as input and produces a single token result. This is used to represent the fact that the operand operators are independent of each other.
  4. llvm/utils/TableGen/CodeGenInstruction.h/cpp. Instruction generated by tablegen.

• Questions:

  1. What's the functionality of TokenFactor Node (except grouping Loads and Exports)? How does it interact with instruction scheduling, register allocating and alias analysis?