[all-commits] [llvm/llvm-project] 62dd44: [VectorCombine] fix cost calc for extract-cmp

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  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 62dd44d76da9aa596fb199bda8b1e8768bb41033
      https://github.com/llvm/llvm-project/commit/62dd44d76da9aa596fb199bda8b1e8768bb41033
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2020-02-16 (Sun, 16 Feb 2020)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/VectorCombine.cpp
    M llvm/test/Transforms/VectorCombine/X86/extract-cmp.ll

  Log Message:
  -----------
  [VectorCombine] fix cost calc for extract-cmp

getOperationCost() is not the cost we wanted; that's not the
throughput value that the rest of the calculation uses.

We may want to switch everything in this code to use the
getInstructionThroughput() wrapper to avoid these kinds of
problems, but I'll look at that as a follow-up because that
can create other logical diffs via using optional parameters
(we'd need to speculatively create the vector instruction to
make a fair(er) comparison).