The optimizer is not disabled, few global optimizations are. The speedup is mostly the result of not having to reparse the headers, reinstantiate and codegen th

The optimizer is not disabled, few global optimizations are. The speedup is mostly the result of not having to reparse the headers, reinstantiate and codegen the generated templated code rather than skip minor opts. This is really slow process that frequently needlessly repeated on multiple compile units. We are looking into this tradeoff, maybe making the decision user-configurable or based on opt. level.