That depends on the project. There definitely are projects in which micro-optimizations such as this wouldn't be beneficial for one reason or another, but there definitely also are ones where they're make-or-break. For those, C is pretty good, and you're not fighting against the language (or the core intent of the language at least).

(I'd guesstimate that micro-optimizations would go a very long way in improving performance of nearly every program anywhere, but I don't have much data on that besides the couple projects where I've tried to care about performance, and having achieved pretty decent results)