[OpenMP][libomptarget] Add data sharing support in libomptarget

Summary: This patch extends the libomptarget functionality in patch D14254 with support for the data sharing scheme for supporting implicitly shared variables. The runtime therefore maintains a list of references to shared variables.

Reviewers: carlo.bertolli, ABataev, Hahnfeld, grokos, caomhin, hfinkel

Reviewed By: Hahnfeld, grokos

Subscribers: guansong, llvm-commits, openmp-commits

Differential Revision: https://reviews.llvm.org/D41485

llvm-svn: 324495

1 files changed, 8 insertions, 0 deletions

diff --git a/openmp/libomptarget/deviceRTLs/nvptx/src/parallel.cu b/openmp/libomptarget/deviceRTLs/nvptx/src/parallel.cu
index d4546284fac..0b9ebd401f8 100644
--- a/openmp/libomptarget/deviceRTLs/nvptx/src/parallel.cu
+++ b/openmp/libomptarget/deviceRTLs/nvptx/src/parallel.cu
@@ -214,10 +214,16 @@ EXTERN void __kmpc_kernel_end_convergent_parallel(void *buffer) {
 //
 // This routine is always called by the team master..
 EXTERN void __kmpc_kernel_prepare_parallel(void *WorkFn,
+                                           void ***SharedArgs, int32_t nArgs,
                                            int16_t IsOMPRuntimeInitialized) {
   PRINT0(LD_IO, "call to __kmpc_kernel_prepare_parallel\n");
   omptarget_nvptx_workFn = WorkFn;
 
+  if (nArgs > 0) {
+    omptarget_nvptx_sharedArgs.EnsureSize(nArgs);
+    *SharedArgs = omptarget_nvptx_sharedArgs.GetArgs();
+  }
+
   if (!IsOMPRuntimeInitialized)
     return;
 
@@ -317,11 +323,13 @@ EXTERN void __kmpc_kernel_prepare_parallel(void *WorkFn,
 //
 // Only the worker threads call this routine.
 EXTERN bool __kmpc_kernel_parallel(void **WorkFn,
+                                   void ***SharedArgs,
                                    int16_t IsOMPRuntimeInitialized) {
   PRINT0(LD_IO | LD_PAR, "call to __kmpc_kernel_parallel\n");
 
   // Work function and arguments for L1 parallel region.
   *WorkFn = omptarget_nvptx_workFn;
+  *SharedArgs = omptarget_nvptx_sharedArgs.GetArgs();
 
   if (!IsOMPRuntimeInitialized)
     return true;