So, trying to hunt an strange issue with Windows scons builds of filebrowser work, I found that our attomic operations (defined in intern/atomic/atomci_ops.h) do not return the same things on MSVC than with other OS/compilers.
With GCC & co we use `__sync_add_and_fetch`, on OSX, `OSAtomicAdd64`, with MSVC `InterlockedExchangeAdd64`, and have a fallback implementation in plain assembler. According to documentations (and my limited asm understanding), MSVC version returns the value of `*p` *before* the operation, while all others return it *after* the operation (i.e. return the result of the operation). https://gcc.gnu.org/onlinedocs/gcc-5.1.0/gcc/_005f_005fsync-Builtins.html https://msdn.microsoft.com/en-us/library/windows/desktop/ms683599(v=vs.85).aspx https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man3/OSAtomicAdd64.3.html I doubt this is desired behavior, and think it could easily generate nasty bug some day… MSVC does not seem to have a 'return value after operation' variant from quick look at the doc? Maybe we should just remove the MSVC case completely and use asm version instead? Bastien _______________________________________________ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
