/test/testatomic.c performs absolutely basic tests to show that the function work as expected. Need a second test to do more detailed tests.

/include/SDL_atomic.h provides declarations for all included functions.

/src/atomic/linux/SDL_atomic.c provided all the functions. On a generic built the 64 bit functions work, but they are emulated. On a build for -march=pentium and above the 64 bit functions use native instructions
/src/atomic/dummy/SDL_atomic.c emulates all the operations using SDL_mutex.h.
/src/atomic/win32/SDL_atomic.c is a copy of dummy
/src/atomic/macosx/SDL_atomic.s is a copy of dummy

These versions of SDL_atomic.c provide a frame work for building the library with a mixture of native and emulated functions. This allows the whole library to be provided on all platforms. (I hope.)
I hope this fits with the SDL philosophy of either providing a common subset or emulating when the platform is missing a feature.

I have not added dummy, macosx, or win32 to the build. They are there as place holders for future work.

I have modified congifure.in to compile sources in /src/atomic/linux. (The SDL configure.in file is an amazing piece of work and I hope I didn't mess it up. :-)

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%403671