LLVM

LLVM

3.2

Install:

cd /path/to
mkdir llvm32
wget http://llvm.org/releases/3.2/llvm-3.2.src.tar.gz
wget http://llvm.org/releases/3.2/clang-3.2.src.tar.gz
tar xzf llvm-3.2.src.tar.gz
cd /path/to/llvm32/llvm-3.2.src/tools/
tar xzf ../../clang-3.2.src.tar.gz
cd /path/to/llvm32
mkdir llvm-build
cd /path/to/llvm32/llvm-build
../llvm-3.2.src/configure --enable-optimized --prefix=/path/to/llvm32/llvm-install
REQUIRES_RTTI=1 make -j3
make install

Use:

export PATH=/path/to/llvm32/llvm-install/bin:$PATH

with Python

llvmpy

export PATH=/path/to/llvm32/llvm-install/bin:$PATH
virtualenv llvmpy_llvm32.env
. llvmpy_llvm32.env/bin/activate
git clone git@github.com:llvmpy/llvmpy.git llvmpy.git
cd llvmpy.git
git checkout 0.12.5
LLVM_CONFIG_PATH=/path/to/llvm32/llvm-install/bin/llvm-config python setup.py install
cd ..
python -c "import llvm; llvm.test()"

llvm_cbuilder

set of Python-contexts you can use to write C-like constructs in Python which generates llvmpy code directly.
Similar to llpython it allows you to build llvm IR without using the llvmpy interface directly.

llpython

• on Github

The primary goal of the llpython package is to provide a Python dialect/subset that maps directly to LLVM code.
LLPython differs from its originating LLVM translator, Numba, in the following aspects:

• LLPython code is not intended to work in Python if not translated and wrapped.
• The LLPython translator only uses LLVM types.
• LLPython is explicitly typed, and does not support type inference. LLPython does not support implicit casts, all casts must be explicit.
• LLPython supports code that directly calls the C API, the Python C API, and the llvm.core.Builder methods.

We developed LLPython with the initial goal of simplifying writing LLVM code.

TODO not clear yet from the doc how to use it...

Numba

Numba is a NumPy aware dynamic compiler for Python. It creates LLVM bit-code from Python syntax and then creates a wrapper around that bitcode to call from Python.

• 0.13 doc
• on Github
• Numba Python bytecode to LLVM translator (video)

pycc allows users to compile Numba functions into a shared library. The user writes the functions, exports them and the compiler will import the module, collect the exported functions and compile them to a shared library. Below is an example:

from numba import *
def mult(a, b):
    return a * b
export('mult f8(f8, f8)'))(mult)
export(['multf f4(f4, f4)', 'multi i4(i4, i4)'])(mult)
export('multc c16(c16, c16)'))(mult)

Pyston

by Dropbox

• https://tech.dropbox.com/2014/04/introducing-pyston-an-upcoming-jit-based-python-implementation/

Not mature yet

old attempts

• llvm-py
• RPython
• Unladen Swallow
• py2llvm