[all-commits] [llvm/llvm-project] 3274cd: [Clang][OpenMP] Remove the mandatory flush for cap...

[Shilei Tian via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 3274cdc83ecdf2af569ad4f564d55d0e43b1072e
      https://github.com/llvm/llvm-project/commit/3274cdc83ecdf2af569ad4f564d55d0e43b1072e
  Author: Shilei Tian <tianshilei1992 at gmail.com>
  Date:   2021-07-26 (Mon, 26 Jul 2021)

  Changed paths:
    M clang/lib/CodeGen/CGStmtOpenMP.cpp
    M clang/test/OpenMP/atomic_capture_codegen.cpp

  Log Message:
  -----------
  [Clang][OpenMP] Remove the mandatory flush for capture for OpenMP 5.1

In OpenMP 5.1:
> If the `write` or `update` clause is specifieded, the atomic operation is not an atomic conditional update for which the comparison fails, and the effective memory ordering is `release`, `acq_rel`, or `seq_cst`, the strong flush on entry to the atomic operation is also a release flush. If the `read` or `update` clause is specified and the effective memory ordering is `acquire`, `acq_rel`, or `seq_cst` then the strong flush on exit from the atomic operation is also an acquire flush.

In OpenMP 5.0:
> If the `write`, `update`, or **`capture`** clause is specified and the `release`, `acq_rel`, or `seq_cst` clause is specified then the strong flush on entry to the atomic operation is also a release flush. If the `read` or `capture` clause is specified and the `acquire`, `acq_rel`, or `seq_cst` clause is specified then the strong flush on exit from the atomic operation is also an acquire flush.

>From my understanding, in OpenMP 5.1, `capture` is removed from the requirement for flush, therefore we don't have to enforce it.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D100768