Setting compiling arguments

[Bitiquinho]

Hi, I want to know if it's possible to set my CXXFLAGS and LDFLAGS when compiling the game from svn, so that I can test possible performance gains with -Ofast and -flto (Link Time Optimizations) options. There's is no configure script for that, so can just I do the same way with update_workspaces script ? Like this:

CXXFLAGS="-DNDEBUG -Ofast -flto -march=native -mtune=core2 -msse -msse2" LDFLAGS="-DNDEBUG -Ofast -flto -march=native -mtune=core2 -msse -msse2" ./update-workspaces.sh

Sorry for possible bad english and thanks in advice.

[Yves]

Check premake4.lua in 0ad/build/premake.

If you change anything in this file you have to run update-workspaces again and it will add the flags to the makefiles.

The other way for temporary tests is to edit the makefiles directly in build/workspaces/gcc.

[Bitiquinho]

Thanks for the quick answer. I'll experiment a little.

[historic_bruno]

You could also pass --minimal-flags to update-workspaces, which disables most of what premake4.lua adds, then set whatever options you want in CXXFLAGS/LDFLAGS as you said.

[fabio]

See also http://trac.wildfiregames.com/ticket/1755 for how to modify premake4.lua for LTO.

Did you do some tests?

[Bitiquinho]

LTO build fails (gcc 4.8.0 here, 4.8.1 not in the repositories yet). Without -flto option I can build successfully but dont get much improvement over the binary release.

[quantumstate]

What failure do you get with LTO?