CXX=clang++ ./configure --enable-simd=AVX CXXFLAGS="-mavx -O3 -I/opt/local/include/openmpi-mp/ -std=c++11" LDFLAGS=-L/opt/local/lib/openmpi-mp/ LIBS="-lmpi -lmpi_cxx"  --enable-comms=mpi
CXX=clang++ ./configure --enable-simd=AVX CXXFLAGS="-mavx -g -I/opt/local/include/openmpi-mp/ -std=c++11" LDFLAGS=-L/opt/local/lib/openmpi-mp/ LIBS="-lmpi -lmpi_cxx"  --enable-comms=mpi
CXX=clang++ ./configure --enable-simd=AVX CXXFLAGS="-mavx -g  -std=c++11" LDFLAGS= LIBS=-lmpi  --enable-comms=fake
CXX=clang++ ./configure --enable-simd=AVX CXXFLAGS="-mavx -g  -std=c++11" LDFLAGS= LIBS=-lmpi  --enable-comms=none