Don't really have time to bisect this but posting FYI.

Maybe pyrit benchmark is the glxgears of benchmarks - if so please say so and
I'll ignore it :-)

Status Que for my R9 270X pyrit 0.3.0 since I got it in May has been around -

Computed 75761.96 PMKs/s total.
#1: 'OpenCL-Device 'AMD PITCAIRN'': 73256.9 PMKs/s (RTT 0.8)
#2: 'CPU-Core (SSE2)': 743.3 PMKs/s (RTT 2.9)
#3: 'CPU-Core (SSE2)': 741.3 PMKs/s (RTT 2.8)
#4: 'CPU-Core (SSE2)': 740.2 PMKs/s (RTT 2.9)
#5: 'Network-Clients': 0.0 PMKs/s (RTT 0.0)

This was kernel agd5f drm-fixes-3.16-wip

I noticed yesterday after trying agd5f drm-next-3.17-rebased-on-fixes that I
lost around 10,000 PMKs/s with the newer kernel.

Both were with yesterdays mesa but llvm was older say a couple of weeks.

Updated llvm and mesa today and it's regressed more on both kernels - 

drm-fixes-3.16-wip

Computed 58233.89 PMKs/s total.
#1: 'OpenCL-Device 'AMD PITCAIRN'': 56076.6 PMKs/s (RTT 1.1)
#2: 'CPU-Core (SSE2)': 753.6 PMKs/s (RTT 2.9)
#3: 'CPU-Core (SSE2)': 754.5 PMKs/s (RTT 2.9)
#4: 'CPU-Core (SSE2)': 753.0 PMKs/s (RTT 2.9)
#5: 'Network-Clients': 0.0 PMKs/s (RTT 0.0)

drm-next-3.17-rebased-on-fixes

Computed 52379.38 PMKs/s total.
#1: 'OpenCL-Device 'AMD PITCAIRN'': 48822.1 PMKs/s (RTT 1.2)
#2: 'CPU-Core (SSE2)': 753.8 PMKs/s (RTT 2.9)
#3: 'CPU-Core (SSE2)': 754.9 PMKs/s (RTT 3.0)
#4: 'CPU-Core (SSE2)': 754.8 PMKs/s (RTT 2.9)
#5: 'Network-Clients': 0.0 PMKs/s (RTT 0.0)