[OpenMP][NVPTX] Added forward declaration to pave the way for building deviceRTLs with OpenMP
Once we switch to build deviceRTLs with OpenMP, primitives and CUDA
intrinsics cannot be used directly anymore because `__device__` is not recognized
by OpenMP compiler. To avoid involving all CUDA internal headers we had in `clang`,
we forward declared these functions. Eventually they will be transformed into
right LLVM instrinsics.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D95058
GitOrigin-RevId: 33a5d212c6198af2bd902bb8e4cfd0f0bec0114f
diff --git a/libomptarget/deviceRTLs/nvptx/src/target_impl.cu b/libomptarget/deviceRTLs/nvptx/src/target_impl.cu
index ffc7498..75945e3 100644
--- a/libomptarget/deviceRTLs/nvptx/src/target_impl.cu
+++ b/libomptarget/deviceRTLs/nvptx/src/target_impl.cu
@@ -16,6 +16,23 @@
#include <cuda.h>
+// Forward declaration of CUDA primitives which will be evetually transformed
+// into LLVM intrinsics.
+extern "C" {
+unsigned int __activemask();
+unsigned int __ballot(unsigned);
+// The default argument here is based on NVIDIA's website
+// https://developer.nvidia.com/blog/using-cuda-warp-level-primitives/
+int __shfl_sync(unsigned mask, int val, int src_line, int width = WARPSIZE);
+int __shfl(int val, int src_line, int width = WARPSIZE);
+int __shfl_down(int var, unsigned detla, int width);
+int __shfl_down_sync(unsigned mask, int var, unsigned detla, int width);
+void __syncwarp(int mask);
+void __threadfence();
+void __threadfence_block();
+void __threadfence_system();
+}
+
DEVICE void __kmpc_impl_unpack(uint64_t val, uint32_t &lo, uint32_t &hi) {
asm volatile("mov.b64 {%0,%1}, %2;" : "=r"(lo), "=r"(hi) : "l"(val));
}
