[all-commits] [llvm/llvm-project] 7334b3: [SystemZ] Reimplement the i8/i16 compare-and-swap ...

[Jonas Paulsson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 7334b3dc3ea4dbb525faaa6a930687aaecf38ae0
      https://github.com/llvm/llvm-project/commit/7334b3dc3ea4dbb525faaa6a930687aaecf38ae0
  Author: Jonas Paulsson <paulsson at linux.vnet.ibm.com>
  Date:   2021-03-03 (Wed, 03 Mar 2021)

  Changed paths:
    M llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
    M llvm/lib/Target/SystemZ/SystemZISelLowering.h
    M llvm/test/CodeGen/SystemZ/cmpxchg-01.ll
    M llvm/test/CodeGen/SystemZ/cmpxchg-02.ll
    M llvm/test/CodeGen/SystemZ/cmpxchg-05.ll

  Log Message:
  -----------
  [SystemZ] Reimplement the i8/i16 compare-and-swap logic.

Even though the implementation in emitAtomicCmpSwapW() was correct, it made
Valgrind report an error. Instead of using a RISBG on CmpVal, an LL[CH]R can
be made on the OldVal, and the problem is avoided.

Review: Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D97604