Comment # 5 on bug 80584 from dex+fdobugzilla@dragonslave.de

I can confirm this for PITCAIRN as well.

Card: VGA compatible controller: Advanced Micro Devices [AMD] nee ATI Pitcairn
      Subsystem: Micro-Star International Co., Ltd. Device 3036

Kernel: 3.18.0-rc7
libdrm: 2.4.58
mesa: git-gc97cbd7
llvm: 3.5