Recommended compiler version and flags for Linux x86_64

Hi, I'm currently building and testing MonetDB on CentOS7, x86_64. I was wondering about the recommended compiler version and compiler flags. So far I'm using gcc 9 and specifically enabled SSE3 extensions (though I did not notice any performance gain). Here's my cmake command cmake3 -DCMAKE_C_FLAGS="pthread -msse3 -O -Wall" -DCMAKE_INSTALL_PREFIX=../install ../MonetDB Is there a list of recommended compiler flags? Kind regards, Daniel