At least on my system (Rx 480) this combination of Mesa and LLVM versions causes different colour issues with different desktops. With Xfce every PNG icon in the menu and the window borders are all drawn with a red value of 255, while on Gnome BMP icons are drawn with a red value of 0. The same issue is known for Arch Linux, and the suggested fix for it is to stick to llvm-3.9.0 for the moment: https://bbs.archlinux.org/viewtopic.php?id=221169 Sadly I do not know (yet) if this is an llvm bug, or if it's an incompatibility between mesa 13.0.2 and llvm 3.9.1.
Here's the upstream bug report: https://bugs.freedesktop.org/show_bug.cgi?id=99078
Created attachment 458230 [details, diff] llvm-3.9.1 amdgpu oversaturation fix a temporary revert patch against llvm-3.9.1 fix the color issue.
*** This bug has been marked as a duplicate of bug 603858 ***