-EV to use lower ISO when shooting then + exposure in post process for a cleaner image?

Let's say in certain conditions I need ISO 6400 for a proper exposure. But instead I use -1 EV and ISO 3200. Then in post process, I add 1 stop of exposure. Would this give me a cleaner image than using ISO 6400 with a proper exposure?

Basically the question is does + exposure in post processing compromise image quality in any way? Thanks.