[all-commits] [llvm/llvm-project] 6a18a9: [SLP] Look-ahead operand reordering heuristic.

[vporpo via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 6a18a9548761b266b28a49f705a568677c24b59b
      https://github.com/llvm/llvm-project/commit/6a18a9548761b266b28a49f705a568677c24b59b
  Author: Vasileios Porpodas <vasileios.porpodas at intel.com>
  Date:   2019-11-11 (Mon, 11 Nov 2019)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
    M llvm/test/Transforms/SLPVectorizer/AArch64/transpose.ll
    M llvm/test/Transforms/SLPVectorizer/X86/lookahead.ll

  Log Message:
  -----------
  [SLP] Look-ahead operand reordering heuristic.

Summary: This patch introduces a new heuristic for guiding operand reordering. The new "look-ahead" heuristic can look beyond the immediate predecessors. This helps break ties when the immediate predecessors have identical opcodes (see lit test for examples).

Reviewers: RKSimon, ABataev, dtemirbulatov, Ayal, hfinkel, rnk

Reviewed By: RKSimon, dtemirbulatov

Subscribers: xbolva00, Carrot, hiraditya, phosek, rnk, rcorcs, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60897