[OpenMP][libomptarget] Add global memory data sharing support for master-worker sharing.
Summary:
This patch adds support for the sharing of variables from the master thread of a team to the worker threads of the team.
The runtime uses a stack structure implemented as a doubly-linked list of slots with each slot having the exact same size as the size requested. This implementation leverages existing data structures. The runtime functions are added as separate functions to avoid interfering with the current interface.
Limitations to be addressed in future patches:
- This current patch only employs global memory. In a future patch we will enable to usage for shared memory as an optimization.
- Allow the allocation of several requested sizes in the same slot.
Reviewers: ABataev, grokos, caomhin, carlo.bertolli
Reviewed By: grokos
Subscribers: Hahnfeld, guansong, openmp-commits
Differential Revision: https://reviews.llvm.org/D44260
llvm-svn: 327440
diff --git a/openmp/libomptarget/deviceRTLs/nvptx/src/interface.h b/openmp/libomptarget/deviceRTLs/nvptx/src/interface.h
index f314443..34e33d1 100644
--- a/openmp/libomptarget/deviceRTLs/nvptx/src/interface.h
+++ b/openmp/libomptarget/deviceRTLs/nvptx/src/interface.h
@@ -483,11 +483,20 @@
int32_t *LaneId, int32_t *NumLanes);
EXTERN void __kmpc_kernel_end_convergent_simd(void *buffer);
+
+EXTERN void __kmpc_data_sharing_init_stack();
+EXTERN void *__kmpc_data_sharing_push_stack(size_t size, int16_t UseSharedMemory);
+EXTERN void __kmpc_data_sharing_pop_stack(void *a);
+EXTERN void __kmpc_begin_sharing_variables(void ***GlobalArgs, size_t nArgs);
+EXTERN void __kmpc_end_sharing_variables();
+EXTERN void __kmpc_get_shared_variables(void ***GlobalArgs);
+
// The slot used for data sharing by the master and worker threads. We use a
// complete (default size version and an incomplete one so that we allow sizes
// greater than the default).
struct __kmpc_data_sharing_slot {
__kmpc_data_sharing_slot *Next;
+ __kmpc_data_sharing_slot *Prev;
void *DataEnd;
char Data[];
};