according to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100839
the real compiler flag enabling this bullshit isn't
-fexpensive-optimizations but -ffp-contract=fast which for some(*)
reason is default in optimized builds.
I think it's best to disabled that optimization globally in case it
also breaks other code (I really don't want to spend several days to
hunt such an idiot bug again). I really doubt it makes any measurable
performance difference.
As https://twitter.com/stephentyrone/status/1399424911328874499 says
that clang might also enable this in the future (though to =on instead
of =fast which should be a bit saner but would still break our code),
just set this option for all GCC-ish compilers incl. clang.
(*) the reason of course is that GCC developers don't develop GCC for
their users but to win idiotic SPEC benchmarks
Only happend if `ONATIVE` was enabled (or some other flag was set
that enables the FMA extension), the root cause was that the cross
product didn't return 0 when it should, but a small value < 0.
Caused some faces to be missing in maps compiled with dmap.
https://github.com/RobertBeckebans/RBDOOM-3-BFG/issues/436#issuecomment-851061826
has lots of explanation.
I think this is a compiler bug, this commit works around it.
fixes#147
Don't include the lazy precompiled.h everywhere, only what's
required for the compilation unit.
platform.h needs to be included instead to provide all essential
defines and types.
All includes use the relative path to the neo or the game
specific root.
Move all idlib related includes from idlib/Lib.h to precompiled.h.
precompiled.h still exists for the MFC stuff in tools/.
Add some missing header guards.
