[PATCH] D48478: [RegisterCoalescer] Improve handling of COPY instructions with identical value numbers

[Tim Renouf via Phabricator via llvm-commits]

tpr created this revision.
Herald added subscribers: llvm-commits, nhaehnle, qcolombet, MatzeB.

This subsumes Krzysztof's https://reviews.llvm.org/D48102, which itself was an alternative to https://reviews.llvm.org/D48032.

It does not include Krzysztof's 'Fix the "cannot join subranges" issue
caused by redefining an undef value' part of https://reviews.llvm.org/D48102, on the basis that
there is a different fix for that on https://reviews.llvm.org/D35073 that we need to refine and
upstream.

Change-Id: I73363db649916046eff58854c957d41a06157b3b


Repository:
  rL LLVM

https://reviews.llvm.org/D48478

Files:
  lib/CodeGen/RegisterCoalescer.cpp
  test/CodeGen/AMDGPU/coalescer-extend-pruned-subrange.mir
  test/CodeGen/AMDGPU/coalescing-subranges-another-copymi-not-live.mir
  test/CodeGen/AMDGPU/coalescing-subranges-another-prune-error.mir
  test/CodeGen/AMDGPU/coalescing-with-subregs-bad-identical.mir
  test/CodeGen/AMDGPU/coalescing-with-subregs-in-loop-bug.mir

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D48478.152454.patch
Type: text/x-patch
Size: 109532 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20180622/6e1a7bef/attachment.bin>