[all-commits] [llvm/llvm-project] bbc983: [DAG] Retain nuw flags when reassociating adds

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: bbc983d33a17b87012c18053a816a8984ab191ca
      https://github.com/llvm/llvm-project/commit/bbc983d33a17b87012c18053a816a8984ab191ca
  Author: David Green <david.green at arm.com>
  Date:   2023-04-20 (Thu, 20 Apr 2023)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/test/CodeGen/Thumb2/mve-vhadd.ll

  Log Message:
  -----------
  [DAG] Retain nuw flags when reassociating adds

Given two adds that are both nuw, they will still be nuw after being
reassociated. (They only increase in value and at no point wrap).
https://alive2.llvm.org/ce/z/JrYM6H

Differential Revision: https://reviews.llvm.org/D148804