| Sure, i'll stick to bugs invisible with the library, and visible without it: If you've inserted compiler barriers it can't move code across, the compiler will no longer perform the same optimizations with and without your debug library. Those optimizations often make bugs visible, because variables no longer have the value you expect them to at the time you expect it, etc. Add in threads, and the problem gets worse: http://preshing.com/20120515/memory-reordering-caught-in-the... Look at the behavior this has with and without the barrier.
It's buggy without it. With it, it's fine. This is exactly equivalent to: Without the debugging library, the code is clearly buggy and doesn't work in user-visible ways. With the debugging library, if i insert a breakpoint where the current asm barrier is, it now behaves correctly 100% of the time, even though it's broken. |