[all-commits] [llvm/llvm-project] 8953ec: [InstCombine] reassociate diff of sums into sum of...

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  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 8953ecf22bcf665ffb06399a97265ab71aebebf8
      https://github.com/llvm/llvm-project/commit/8953ecf22bcf665ffb06399a97265ab71aebebf8
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2020-06-22 (Mon, 22 Jun 2020)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
    M llvm/test/Transforms/InstCombine/vector-reductions.ll
    M llvm/test/Transforms/PhaseOrdering/X86/vector-reductions.ll

  Log Message:
  -----------
  [InstCombine] reassociate diff of sums into sum of diffs

This is the integer sibling to D81491.

(a[0] + a[1] + a[2] + a[3]) - (b[0] + b[1] + b[2] +b[3]) -->
(a[0] - b[0]) + (a[1] - b[1]) + (a[2] - b[2]) + (a[3] - b[3])

Removing the "experimental" from these intrinsics is likely
not too far away.