commit 926938a039dbca89d50348b06cf7cda4924c60f8
author Alexey Bataev <a.bataev@hotmail.com> Wed May 22 19:50:32 2019 +0000
committer Alexey Bataev <a.bataev@hotmail.com> Wed May 22 19:50:32 2019 +0000
tree 598c3dd691ace052d265ea91935f19505dd54894
parent f8e8d598bf8b2725baf87892119e6952819fce34

[OPENMP][NVPTX]Fix barriers and parallel level counters, NFC.

Summary:
Parallel level counter should be volatile to prevent some dangerous
optimiations by the ptxas. Otherwise, ptxas optimizations lead to
undefined behaviour in some cases.
Also, use __threadfence() for #pragma omp flush and if the barrier
should not be used (we have only one thread in the team), still perform
flush operation since the standard requires implicit flush when
executing barriers.

Reviewers: gtbercea, kkwli0, grokos

Subscribers: guansong, jfb, jdoerfert, openmp-commits, caomhin

Tags: #openmp

Differential Revision: https://reviews.llvm.org/D62199

git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@361421 91177308-0d34-0410-b5e6-96231b3b80d8