[RoboCop]

Well I wasn't sure if adding MMX and SSE were necessary as well as adding too many opt flags as well as using -O3 could cause some adverse effects as well increase the build size. As for using like -march=pentium4 or higher may not be compatible with the old GoldSrc engine as it was released since 1997/1998 and maybe pushed to it's limit. Also some older compilers like GCC 4.8 appear to recompile those builds in a smaller size but won't have the latest C++14 nor C++17 standard features - if I am not mistaken.