[all-commits] [llvm/llvm-project] 1ce8a5: [X86] Only look up boolean reduction cost tables i...

[topperc via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 1ce8a5b385a1e2987ecf49080f983615c59f6c73
      https://github.com/llvm/llvm-project/commit/1ce8a5b385a1e2987ecf49080f983615c59f6c73
  Author: Craig Topper <craig.topper at gmail.com>
  Date:   2019-10-26 (Sat, 26 Oct 2019)

  Changed paths:
    M llvm/lib/Target/X86/X86TargetTransformInfo.cpp

  Log Message:
  -----------
  [X86] Only look up boolean reduction cost tables if the reduction is not pairwise.

Summary:
We don't pattern match pairwise shuffles in SelectionDAG. So we
should only return the optimized costs if its not a pairwise
shuffle.

I think SLP vectorizer gives priority to non pairwise shuffle if
the cost is the same. And the look up for reduction intrinsics
passes false for the pairwise flag. So this probably has no real
effect today.

Reviewers: RKSimon

Reviewed By: RKSimon

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69083