# Getting Started: Building and Installing Polly

## Automatic

There is a script available to automatically checkout, update, build, and test Polly. This script contains all the commands that are subsequently described on this webpage. The automatic installation consists of four simple steps:

    mkdir polly && cd polly
    wget http://polly.llvm.org/polly.sh
    chmod +x polly.sh
    ./polly.sh

## Manual

### Get the code

The Polly source code is available in the LLVM SVN repository as well as through an official git mirror. It is added to the tools directory of the llvm sources. Polly and LLVM need to be checked out at the same time. Checkouts from different dates may not work!

#### Set the directory layout:

    export BASE=`pwd`
    export LLVM_SRC=${BASE}/llvm
    export POLLY_SRC=${LLVM_SRC}/tools/polly

    # Also build the matching clang-version (optional)
    export CLANG_SRC=${LLVM_SRC}/tools/clang

#### SVN

    svn checkout http://llvm.org/svn/llvm-project/llvm/trunk ${LLVM_SRC}
    svn checkout http://llvm.org/svn/llvm-project/polly/trunk ${POLLY_SRC}

    # Also build the matching clang-version (optional)
    svn checkout http://llvm.org/svn/llvm-project/cfe/trunk ${CLANG_SRC}

#### GIT

    git clone http://llvm.org/git/llvm.git ${LLVM_SRC}
    git clone http://llvm.org/git/polly.git ${POLLY_SRC}

    # Also build the matching clang-version (optional)
    git clone http://llvm.org/git/clang.git ${CLANG_SRC}

### Prerequisites

- libgmp
- isl

#### libgmp

Install libgmp (library + developer package) through the package management system of your operating system.

#### isl

Polly is tested with a fixed version of isl. To obtain the source code of isl use checkout_isl.sh as available in ${POLLY_SRC}/utils/checkout_isl.sh.

#### Set the directory layout:

    export ISL_SRC=${BASE}/isl_src
    export ISL_INSTALL=${BASE}/isl_install

#### First installation

    ${POLLY_SRC}/utils/checkout_isl.sh ${ISL_SRC}
    cd ${ISL_SRC}
    ./configure --prefix=${ISL_INSTALL}
    make
    make install
    cd ${BASE}

#### Update the installation

Updating isl may become necessary, if Polly uses a feature only available in a recent version of isl.

    ${POLLY_SRC}/utils/checkout_isl.sh ${ISL_SRC}
    cd ${ISL_SRC}
    make
    make install
    cd ${BASE}

### Build Polly

To build Polly you can either use the autoconf or the cmake build system. At the moment only the autoconf build system allows to run the llvm test-suite and only the cmake build system allows to run 'make check-polly'.

#### Set the directory layout:

    export LLVM_BUILD=${BASE}/llvm_build
    mkdir ${LLVM_BUILD}
    cd ${LLVM_BUILD}

#### CMake

    cmake -DCMAKE_PREFIX_PATH=${ISL_INSTALL} ${LLVM_SRC}
    make

#### Autoconf

    ${LLVM_SRC}/configure --with-isl=${ISL_INSTALL}
    make

### Test Polly

To check if Polly works correctly you can run make check-polly for the cmake build or make check-polly -C tools/polly/test/ for the autoconf build.

If you get something like "... libisl.so.9: cannot open shared object file ..", it is because you installed isl to a non-standard path, and libisl could not be found. To solve this issue, you need to append the path of parent directory of libisl, i.e. ${ISL_INSTALL}/lib, to LD_LIBRARY_PATH by:

    export LD_LIBRARY_PATH=${ISL_INSTALL}/lib:$LD_LIBRARY_PATH

Also try the above command if you get errors such as: `undefined symbol: isl_ctx_get_max_operations`

If you get an error in one of the python files, your system probably uses python3 as default python interpreter. This is the case, for instance, under Arch Linux. To solve this issue, run `cmake` again, but with the added argument: `-DPYTHON_EXECUTABLE=/usr/bin/python2` (replace `/usr/bin/python2` with the location of the python2 interpreter under your system).

    cmake -DCMAKE_PREFIX_PATH=${ISL_INSTALL} -DPYTHON_EXECUTABLE=/usr/bin/python2 ${LLVM_SRC}

## Optional Features

### Pocc [Supported until LLVM 3.4.2]

Polly can use PoCC as an external optimizer. PoCC is a research project that provides an integrated version of Pluto, an advanced data-locality and tileability optimizer. Polly includes internally already a similar optimizer, such that in general PoCC is not needed. It is only recommended for people who want to compare against a different optimizer.
To use it install PoCC 1.0-rc3.1 (the one with Polly support) and add it to your PATH.

    wget http://www.cse.ohio-state.edu/~pouchet/software/pocc/download/pocc-1.0-rc3.1-full.tar.gz
    tar xzf pocc-1.0-rc3.1-full.tar.gz
    cd pocc-1.0-rc3.1
    ./install.sh
    export PATH=$PATH:`pwd`/bin

You also need to install scoplib-0.2.0 and provide its location to Polly's cmake or configure call.

    wget http://www.cse.ohio-state.edu/~pouchet/software/pocc/download/modules/scoplib-0.2.0.tar.gz
    tar xzf  scoplib-0.2.0.tar.gz
    cd scoplib-0.2.0
    ./configure --enable-mp-version --prefix=/path/to/scoplib/installation
    make && make install