User:Hef/ispc on rpi2

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setup

gcc 4.6 both won't compile latest llvm/clang and will generate an ICE on older versions of clang.

sudo apt-get install cmake gcc-4.8 g++-4.8 bison flex libncurses5-dev subversion

second attempt

export LLVM_HOME=~/projects/llvm_home
export ISPC_HOME=$PWD
export CC=/usr/bin/gcc-4.8
export CXX=/usr/bin/g++-4.8
export CFLAGS="-march=armv7-a -mtune=cortex-a7 -mfpu=neon-vfpv4"
export CXXFLAGS="-march=armv7-a -mtune=cortex-a7 -mfpu=neon-vfpv4"
./alloy.py -b --version=3.5
export PATH=$PATH:$LLVM_HOME/bin-3.5/bin

I should try adding export CFLAGS="-march=armv7-a -mtune=cortex-a7 -mfpu=neon-vfpv4"

first attempt

ninja

git clone git://github.com/martine/ninja.git
cd ninja
git checkout release
./configure.py --bootstrap
sudo cp ninja /usr/local/bin/ninja

clang

git clone http://llvm.org/git/llvm.git
cd llvm/tools
git clone http://llvm.org/git/clang.git
cd ../../..
mkdir llvm-build
cd llvm-build
cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=/usr/bin/gcc-4.8 -DCMAKE_CXX_COMPILER=/usr/bin/g++-4.8 ../llvm -G Ninja
ninja -j1

Ninja will take many hours to complete. I didn't fully test the -j (concurrent build) options to ninja. ninja defaults to 6 on the rpi2. You will run out of memory if you do this. Even if you create larger swap for the pi, swapping to an sd card is a really major performance hit and you will be better of using fewer cores.

self hosted clang

cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=/usr/local/bin/clang -DCMAKE_CXX_COMPILER=/usr/local/bin/clang++ ../llvm -G Ninja

ispc

make ARM_ENABLED=1 -j4