[all-commits] [llvm/llvm-project] cb3f41: [PowerPC] Fix up memory ordering after combining B...

[Nemanja Ivanovic via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cb3f415cd2019df7d14683842198bc4b7a492bc5
      https://github.com/llvm/llvm-project/commit/cb3f415cd2019df7d14683842198bc4b7a492bc5
  Author: Nemanja Ivanovic <nemanja.i.ibm at gmail.com>
  Date:   2022-12-16 (Fri, 16 Dec 2022)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/lib/Target/PowerPC/PPCISelLowering.cpp
    A llvm/test/CodeGen/PowerPC/build-vector-to-ld-chain.ll

  Log Message:
  -----------
  [PowerPC] Fix up memory ordering after combining BV to a load

The combiner for BUILD_VECTOR that merges consecutive
loads into a wide load had two issues:

- It didn't check that the input loads all have the
  same input chain
- It didn't update nodes that are chained to the original
  loads to be chained to the new load

This caused issues with bootstrap when
3c4d2a03968ccf5889bacffe02d6fa2443b0260f was committed.
This patch fixes the issue so it can unblock this commit.

Differential revision: https://reviews.llvm.org/D140046