I’m not the parent but I imagine they’re referring to e.g., some FFTs use different partitioning strategies in different threading environments, which breaks bi

I’m not the parent but I imagine they’re referring to e.g., some FFTs use different partitioning strategies in different threading environments, which breaks bit-perfect replication. There’s also the weirdness that in C++ the floating point environment is thread-local, which can cause all sorts of chaos.