Created attachment 89277 [details]
Screenshot of KDE with purple colors.

I get this too.

Git version from today(15/11) of libdrm, mesa, xorg-server, glamor and xf86-video-ati. Kernel is 3.12.0. Hardware is Radeon HD 7850.

Can you bisect this?  It's possible that this commit is responsible:

    R600/SI: Prefer SALU instructions for bit shift operations
    
    All shift operations will be selected as SALU instructions and then
    if necessary lowered to VALU instructions in the SIFixSGPRCopies pass.
    
    This allows us to do more operations on the SALU which will improve
    performance and is also required for implementing private memory
    using indirect addressing, since the private memory pointers must stay
    in the scalar registers.
    
    This patch includes some fixes from Matt Arsenault.
    
    git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194625 91177308-0d34-0410-b5e6-96231b3b80d8

(In reply to comment #2)
> Can you bisect this?  It's possible that this commit is responsible:
> 
>     R600/SI: Prefer SALU instructions for bit shift operations
>     
>     All shift operations will be selected as SALU instructions and then
>     if necessary lowered to VALU instructions in the SIFixSGPRCopies pass.
>     
>     This allows us to do more operations on the SALU which will improve
>     performance and is also required for implementing private memory
>     using indirect addressing, since the private memory pointers must stay
>     in the scalar registers.
>     
>     This patch includes some fixes from Matt Arsenault.
>     
>     git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194625
> 91177308-0d34-0410-b5e6-96231b3b80d8

After update to the latest git version everything returned to normal. Thanks.