Development tips

This section gives you some tips on the Taichi compiler development. Please make sure you have gone through developer installation.

Workflow of the Taichi compiler

Life of a Taichi kernel is a good place to get started, which explains the whole compilation process step by step.

Folder structure

Key folders: (the following chart can be generated by tree . -L 2)

.
├── benchmarks              # Performance benchmarks
├── docs                    # Documentation
├── examples                # Examples
├── external                # External libraries
├── misc                    # Random yet useful files
├── python                  # Python frontend implementation
│   ├── core                # Loading & interacting with Taichi core
│   ├── lang                # Python-embbed Taichi language & syntax (major)
│   ├── snode               # Structure nodes
│   ├── tools               # Handy end-user tools
│   └── misc                # Miscellaneous utilities
├── taichi                  # The core compiler implementation: C++ source of libtaichi_core.so
│   ├── analysis            # Static analysis passes
│   ├── backends            # Device-dependent code generators/runtime environments
│   ├── codegen             # Code generation base classes
│   ├── common              # Common headers
│   ├── gui                 # GUI system
│   ├── inc                 # Small definition files to be included repeatedly
│   ├── ir                  # Intermediate representation
│   ├── jit                 # Just-In-Time compilation base classes
│   ├── llvm                # LLVM utilities
│   ├── math                # Math utilities
│   ├── platform            # Platform supports
│   ├── program             # Top-level constructs
│   ├── python              # C++/Python interfaces
│   ├── runtime             # LLVM runtime environments
│   ├── struct              # Struct compiler base classes
│   ├── system              # OS-related infrastructure
│   ├── transforms          # IR transform passes
│   └── util                # Miscellaneous utilities
└── tests                   # Functional tests
    ├── cpp                 # Python tests (major)
    └── python              # C++ tests

C++ and Python standards

The C++ part of the Taichi compiler is written in C++17, and the Python part in 3.6+. You can assume that C++17 and Python 3.6 features are always available.

Efficient code navigation across Python/C++

If you are working on the language frontend (Python/C++ interface), you may want to navigate across Python/C++ code. ffi-navigator allows you to jump from Python bindings to their definitions in C++. Please follow their README to set up your editor.

Printing IRs in different stages

When creating a Taichi program using ti.init(arch=desired_arch, **kwargs), pass in the following parameters to make the Taichi compiler print out IRs in different stages:

• print_ir=True: print the Taichi IR transformation process of kernel (excluding accessors) compilation.
• print_accessor_ir=True: print the IR transformation process of data accessors, which are special and simple kernels. This is rarely used, unless you are debugging the compilation of data accessors.
• print_struct_llvm_ir=True: save the emitted LLVM IR by Taichi struct compilers.
• print_kernel_llvm_ir=True: save the emitted LLVM IR by Taichi kernel compilers.
• print_kernel_llvm_ir_optimized=True: save the optimized LLVM IR of each kernel.
• print_kernel_nvptx=True: save the emitted NVPTX of each kernel (CUDA only).

note

Data accessors in Python-scope are implemented as special Taichi kernels. For example, x[1, 2, 3] = 3 will call the writing accessor kernel of x, and print(y[42]) will call the reading accessor kernel of y.

Benchmarking

See Benchmarking and regression tests if your work involves IR optimization.