Merging r266824:

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r266824 | nhaehnle | 2016-04-19 14:58:17 -0700 (Tue, 19 Apr 2016) | 21 lines

AMDGPU/SI: SGPR accounting in getSIProgramInfo must ignore exec_lo/hi

Summary:
A shader stored the live mask (initial exec mask) in an SGPR which was then
spilled during register allocation. The allocator quite reasonably
optimized turned the spill into

  v_writelane_b32 %vgpr, exec_lo, N
  v_writelane_b32 %vgpr, exec_hi, N+1

at the beginning of the shader, confusing the SGPR accounting.

No test case, because si-sgpr-spill.ll together with an upcoming patch for
WQM handling exhibits the problem.

Reviewers: arsenm, tstellarAMD

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D19199

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llvm-svn: 271766