I'm also running a R9 380 and I encountered crashes since 2 weeks before the Stormblood launch or so.
Before, I never had any problems at all. Always had the latest drivers installed.

So in a last desperate effort, I decided to roll back to the 17.1.1 drivers. I've never had a single crash since then. Maybe I'm just lucky. But maybe some of you might want to try the same thing and become lucky, too. ;-)