In macports base in standard_configure.sh there is this line: 6 env PATH=/usr/bin:/bin:/usr/sbin:/sbin CFLAGS="-pipe -Os" ./configure --enable-readline Why do we compile with -Os instead of -O2? As far as I could the only difference, in llvm 4.0.1, is to disable the "libcalls-shrinkwrap" opt pass. -- Eitan Adler