I have been building multiple projects that require sse2 instruction set. Adding -march=native as mentioned in sse2 instruction set not enabled has done the job till now.
However, in the 3 projects I have needed this, the gcc commands in the makefile were easy to locate and editing slightly the makefile worked. Now I tackle a far more complex makefile generated by cmake. I believe it makes more makefiles in other folders and then runs them etc. So just adding a simple -march=native is neither desirable nor easy and will take a considerable amount of time, if it is feasible afterall.
Is there a way to somehow always have sse2 enabled, opposite to now? I googled this but wasn't able to find something.
Given the fact that non of the makefiles I downloaded from github had -march=native inside, it leads me to believe that indeed there might be some way to set this on gcc/g++ level beforehand?
I found this -mfpmath=sse flag but was not able to formulate a correct gcc/g++ command (if that is related).
Can you help me?
You can add the compiler option -march=native in CMakeLists.txt
SET(PROJECT_FLAGS "-march=native")
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${PROJECT_FLAGS }")
Or
add_compile_options(-march=native) # CMake 2.8.12 or newer