[Openmp-commits] [openmp] ab9f3f5 - [OpenMP] Introduce the keepAlive function into the old device RT

[Johannes Doerfert via Openmp-commits]

Author: Johannes Doerfert
Date: 2021-11-04T17:54:56-05:00
New Revision: ab9f3f5d25dc14a9dcffa48389cd1a321d598578

URL: https://github.com/llvm/llvm-project/commit/ab9f3f5d25dc14a9dcffa48389cd1a321d598578
DIFF: https://github.com/llvm/llvm-project/commit/ab9f3f5d25dc14a9dcffa48389cd1a321d598578.diff

LOG: [OpenMP] Introduce the keepAlive function into the old device RT

Reviewed By: ye-luo

Differential Revision: https://reviews.llvm.org/D113110

Added: 
    

Modified: 
    openmp/libomptarget/deviceRTLs/common/src/support.cu

Removed: 
    


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diff  --git a/openmp/libomptarget/deviceRTLs/common/src/support.cu b/openmp/libomptarget/deviceRTLs/common/src/support.cu
index 6dd591325c0b..b3bf550364bd 100644
--- a/openmp/libomptarget/deviceRTLs/common/src/support.cu
+++ b/openmp/libomptarget/deviceRTLs/common/src/support.cu
@@ -226,4 +226,14 @@ void __kmp_invoke_microtask(kmp_int32 global_tid, kmp_int32 bound_tid, void *fn,
   }
 }
 
+namespace _OMP {
+/// Helper to keep code alive without introducing a performance penalty.
+__attribute__((used, weak, optnone)) void keepAlive() {
+  __kmpc_get_hardware_thread_id_in_block();
+  __kmpc_get_hardware_num_threads_in_block();
+  __kmpc_barrier_simple_spmd(nullptr, 0);
+  __kmpc_barrier_simple_generic(nullptr, 0);
+}
+} // namespace _OMP
+
 #pragma omp end declare target