| =========================================================================== |
| Building a JIT: Extreme Laziness - Using Compile Callbacks to JIT from ASTs |
| =========================================================================== |
| |
| .. contents:: |
| :local: |
| |
| **This tutorial is under active development. It is incomplete and details may |
| change frequently.** Nonetheless we invite you to try it out as it stands, and |
| we welcome any feedback. |
| |
| Chapter 4 Introduction |
| ====================== |
| |
| Welcome to Chapter 4 of the "Building an ORC-based JIT in LLVM" tutorial. This |
| chapter introduces the Compile Callbacks and Indirect Stubs APIs and shows how |
| they can be used to replace the CompileOnDemand layer from |
| `Chapter 3 <BuildingAJIT3.html>`_ with a custom lazy-JITing scheme that JITs |
| directly from Kaleidoscope ASTs. |
| |
| **To be done:** |
| |
| **(1) Describe the drawbacks of JITing from IR (have to compile to IR first, |
| which reduces the benefits of laziness).** |
| |
| **(2) Describe CompileCallbackManagers and IndirectStubManagers in detail.** |
| |
| **(3) Run through the implementation of addFunctionAST.** |
| |
| Full Code Listing |
| ================= |
| |
| Here is the complete code listing for our running example that JITs lazily from |
| Kaleidoscope ASTS. To build this example, use: |
| |
| .. code-block:: bash |
| |
| # Compile |
| clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core orcjit native` -O3 -o toy |
| # Run |
| ./toy |
| |
| Here is the code: |
| |
| .. literalinclude:: ../../examples/Kaleidoscope/BuildingAJIT/Chapter4/KaleidoscopeJIT.h |
| :language: c++ |
| |
| `Next: Remote-JITing -- Process-isolation and laziness-at-a-distance <BuildingAJIT5.html>`_ |
