[all-commits] [llvm/llvm-project] c9cebd: [AArch64] Adjust the cost of integer sum reductions

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: c9cebda772cbb6cdfc096c10cbc3cc3826801109
      https://github.com/llvm/llvm-project/commit/c9cebda772cbb6cdfc096c10cbc3cc3826801109
  Author: David Green <david.green at arm.com>
  Date:   2021-07-22 (Thu, 22 Jul 2021)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
    M llvm/test/Analysis/CostModel/AArch64/reduce-add.ll
    M llvm/test/Analysis/CostModel/AArch64/vector-reduce.ll
    M llvm/test/Transforms/SLPVectorizer/AArch64/gather-cost.ll
    M llvm/test/Transforms/SLPVectorizer/AArch64/horizontal.ll

  Log Message:
  -----------
  [AArch64] Adjust the cost of integer sum reductions

This changes the cost to (LT.first-1) * cost(add) + 2, where the cost of
an add is assumed to be 1. This brings it inline with the other
reductions.

Differential Revision: https://reviews.llvm.org/D106240