[all-commits] [llvm/llvm-project] 11dee2: [ARM] Ensure CountReg definition dominates InsertP...

[David Green via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 11dee2eae2f7bba4b12aa1c10f59456238eb9a9d
      https://github.com/llvm/llvm-project/commit/11dee2eae2f7bba4b12aa1c10f59456238eb9a9d
  Author: David Green <david.green at arm.com>
  Date:   2020-11-12 (Thu, 12 Nov 2020)

  Changed paths:
    M llvm/lib/Target/ARM/MVEVPTOptimisationsPass.cpp
    A llvm/test/CodeGen/Thumb2/LowOverheadLoops/count_dominates_start.mir

  Log Message:
  -----------
  [ARM] Ensure CountReg definition dominates InsertPt when creating t2DoLoopStartTP

Of course there was something missing, in this case a check that the def
of the count register we are adding to a t2DoLoopStartTP would dominate
the insertion point.

In the future, when we remove some of these COPY's in between, the
t2DoLoopStartTP will always become the last instruction in the block,
preventing this from happening. In the meantime we need to check they
are created in a sensible order.

Differential Revision: https://reviews.llvm.org/D91287