[all-commits] [llvm/llvm-project] 81ec49: [SDAGBuilder] Handle multi-part arguments in argum...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 81ec494c363d4934e692e8b35e0b3fbbc3de1c2b
      https://github.com/llvm/llvm-project/commit/81ec494c363d4934e692e8b35e0b3fbbc3de1c2b
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2023-06-22 (Thu, 22 Jun 2023)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
    M llvm/test/CodeGen/X86/pr63430.ll

  Log Message:
  -----------
  [SDAGBuilder] Handle multi-part arguments in argument copy elision (PR63430)

When eliding an argument copy, we need to update the chain to ensure
the argument reads are performed before later writes. However, the
code doing this only handled this for the first part of the argument.
If the argument had multiple parts, the chains of the later parts were
dropped. Make sure we preserve all chains.

Fixes https://github.com/llvm/llvm-project/issues/63430.