[all-commits] [llvm/llvm-project] 07ebd7: MCP: Fixed bug with dest overlapping copy source

[Tim Renouf via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 07ebd741546e399f3db0a7c08a7fb1932e14080c
      https://github.com/llvm/llvm-project/commit/07ebd741546e399f3db0a7c08a7fb1932e14080c
  Author: Tim Renouf <tpr.ll at botech.co.uk>
  Date:   2019-11-12 (Tue, 12 Nov 2019)

  Changed paths:
    M llvm/lib/CodeGen/MachineCopyPropagation.cpp
    A llvm/test/CodeGen/AMDGPU/mcp-overlap-after-propagation.mir

  Log Message:
  -----------
  MCP: Fixed bug with dest overlapping copy source

In MachineCopyPropagation, when propagating the source of a copy into
the operand of a later instruction, bail if a destination overlaps
(partly defines) the copy source. If the instruction where the
substitution is happening is also a copy, allowing the propagation
confuses the tracking mechanism.

Differential Revision: https://reviews.llvm.org/D69953

Change-Id: Ic570754f878f2d91a4a50a9bdcf96fbaa240726d