diff --git a/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h b/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h
--- a/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h
+++ b/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h
@@ -136,6 +136,14 @@
 EXTERN void __kmpc_impl_threadfence_block(void);
 EXTERN void __kmpc_impl_threadfence_system(void);
 
+// Calls to the AMDGCN layer (assuming 1D layout)
+EXTERN uint64_t __ockl_get_local_size(uint32_t);
+EXTERN uint64_t __ockl_get_num_groups(uint32_t);
+INLINE int GetThreadIdInBlock() { return __builtin_amdgcn_workitem_id_x(); }
+INLINE int GetBlockIdInKernel() { return __builtin_amdgcn_workgroup_id_x(); }
+INLINE int GetNumberOfBlocksInKernel() { return __ockl_get_num_groups(0); }
+INLINE int GetNumberOfThreadsInBlock() { return __ockl_get_local_size(0); }
+
 // DEVICE versions of part of libc
 extern "C" {
 DEVICE __attribute__((noreturn)) void
diff --git a/openmp/libomptarget/deviceRTLs/common/src/support.cu b/openmp/libomptarget/deviceRTLs/common/src/support.cu
--- a/openmp/libomptarget/deviceRTLs/common/src/support.cu
+++ b/openmp/libomptarget/deviceRTLs/common/src/support.cu
@@ -98,14 +98,6 @@
 //
 ////////////////////////////////////////////////////////////////////////////////
 
-DEVICE int GetThreadIdInBlock() { return threadIdx.x; }
-
-DEVICE int GetBlockIdInKernel() { return blockIdx.x; }
-
-DEVICE int GetNumberOfBlocksInKernel() { return gridDim.x; }
-
-DEVICE int GetNumberOfThreadsInBlock() { return blockDim.x; }
-
 DEVICE unsigned GetWarpId() { return GetThreadIdInBlock() / WARPSIZE; }
 
 DEVICE unsigned GetLaneId() { return GetThreadIdInBlock() & (WARPSIZE - 1); }
diff --git a/openmp/libomptarget/deviceRTLs/common/support.h b/openmp/libomptarget/deviceRTLs/common/support.h
--- a/openmp/libomptarget/deviceRTLs/common/support.h
+++ b/openmp/libomptarget/deviceRTLs/common/support.h
@@ -1,4 +1,4 @@
-//===--------- support.h - NVPTX OpenMP support functions -------- CUDA -*-===//
+//===--------- support.h - OpenMP GPU support functions ---------- CUDA -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -51,10 +51,6 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // get low level ids of resources
-DEVICE int GetThreadIdInBlock();
-DEVICE int GetBlockIdInKernel();
-DEVICE int GetNumberOfBlocksInKernel();
-DEVICE int GetNumberOfThreadsInBlock();
 DEVICE unsigned GetWarpId();
 DEVICE unsigned GetLaneId();
 
diff --git a/openmp/libomptarget/deviceRTLs/nvptx/src/target_impl.h b/openmp/libomptarget/deviceRTLs/nvptx/src/target_impl.h
--- a/openmp/libomptarget/deviceRTLs/nvptx/src/target_impl.h
+++ b/openmp/libomptarget/deviceRTLs/nvptx/src/target_impl.h
@@ -167,4 +167,10 @@
 INLINE void __kmpc_impl_threadfence_block(void) { __threadfence_block(); }
 INLINE void __kmpc_impl_threadfence_system(void) { __threadfence_system(); }
 
+// Calls to the NVPTX layer (assuming 1D layout)
+INLINE int GetThreadIdInBlock() { return threadIdx.x; }
+INLINE int GetBlockIdInKernel() { return blockIdx.x; }
+INLINE int GetNumberOfBlocksInKernel() { return gridDim.x; }
+INLINE int GetNumberOfThreadsInBlock() { return blockDim.x; }
+
 #endif