Comment # 4 on bug 65438 from hadack@gmx.de

I have the same problem on a 7750 CAPE VERDE card.

When starting a xfce session X craches with the error message from above,
starting kde works fine.

bisecting shows this bad commit:

8a72c73032707c7b3c042b716286a1ac33720991 is the first bad commit
commit 8a72c73032707c7b3c042b716286a1ac33720991
Author: Tom Stellard <thomas.stellard@amd.com>
Date:   Mon Jun 3 17:39:46 2013 +0000

    R600/SI: Fixup CopyToReg register class in PostprocessISelDAG()

    The CopyToReg nodes will sometimes try to copy a value from a VGPR to an
    SGPR.  This kind of copy is not possible, so we need to detect
    VGPR->SGPR copies and do something else.  The current strategy is to
    replace these copies with VGPR->VGPR copies and hope that all the users
    of CopyToReg can accept VGPRs as arguments.

    git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183132
91177308-0d34-0410-b5e6-96231b3b80d8