xPC Target Optimizations on compile speed really slow

When I use the xPC Target option to set Compiler Optimizations to On, the compilation line where it compiles the .c file takes a really long time compared to when I set Optimizations to Off. I do notice an improvement in model AverageTET time, so the optimizations are doing something. But what I was curious about is why it takes so much longer to compile the model.c file with optimizations on? My model went from compiling in a few seconds to 2 hours just by setting that option.

[Chethan Pandarinath]

Thomas, do you have any tips on this? We are having similar slow compiles. Not sure if optimization is the culprit in our case, but if you found anything that helps, it'd be great to hear.