AMD's Tom Stellard announced this first release of LLVM 3.9.1 today. This does include some AMDGPU back-end updates plus an assortment of other fixes to LLVM. LLVM 3.9.0 was released back in September so there are a fair amount of fixes in this version.
LLVM 4.0 meanwhile is scheduled for release in February as the next feature release. More details on LLVM 3.9.1 via the announcement.