[all-commits] [llvm/llvm-project] 19e6d5: [LV] Re-use existing compare if possible for diff ...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 19e6d541889f24e21c7a9a6e021aeb82efd4dcb2
      https://github.com/llvm/llvm-project/commit/19e6d541889f24e21c7a9a6e021aeb82efd4dcb2
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2023-11-23 (Thu, 23 Nov 2023)

  Changed paths:
    M llvm/lib/Transforms/Utils/LoopUtils.cpp
    M llvm/test/Transforms/LoopVectorize/runtime-checks-difference-simplifications.ll

  Log Message:
  -----------
  [LV] Re-use existing compare if possible for diff checks.

SCEV simplifying the subtraction may result in redundant compares that
are all OR'd together. Keep track of the generated operands in
SeenCompares, with the key being the pair of operands for the compare.

If we alrady generated the same compare previously, skip it.