[OpenMP 5.0] libomptarget interface for declare mapper functions.

This patch implements the libomptarget runtime interface for OpenMP 5.0
declare mapper functions. The declare mapper functions generated by
Clang will call them to complete the mapping of members.
kmpc_mapper_num_components gets the current number of components for a
user-defined mapper; kmpc_push_mapper_component pushes back one
component for a user-defined mapper.

The design slides can be found at
https://github.com/lingda-li/public-sharing/blob/master/mapper_runtime_design.pptx

Patch by Lingda Li <lildmh@gmail.com>

Differential Revision: https://reviews.llvm.org/D60972

llvm-svn: 367772

openmp/libomptarget/src/exports

@@ -13,6 +13,8 @@ VERS1.0 {
     __tgt_target_data_update_nowait;
     __tgt_target_nowait;
     __tgt_target_teams_nowait;
+    __tgt_mapper_num_components;
+    __tgt_push_mapper_component;
     omp_get_num_devices;
     omp_get_initial_device;
     omp_target_alloc;

openmp/libomptarget/src/interface.cpp

@@ -304,6 +304,28 @@ EXTERN int __tgt_target_teams_nowait(int64_t device_id, void *host_ptr,
                             arg_sizes, arg_types, team_num, thread_limit);
 }
 
+// Get the current number of components for a user-defined mapper.
+EXTERN int64_t __tgt_mapper_num_components(void *rt_mapper_handle) {
+  auto *MapperComponentsPtr = (struct MapperComponentsTy *)rt_mapper_handle;
+  int64_t size = MapperComponentsPtr->Components.size();
+  DP("__tgt_mapper_num_components(Handle=" DPxMOD ") returns %" PRId64 "\n",
+     DPxPTR(rt_mapper_handle), size);
+  return size;
+}
+
+// Push back one component for a user-defined mapper.
+EXTERN void __tgt_push_mapper_component(void *rt_mapper_handle, void *base,
+                                        void *begin, int64_t size,
+                                        int64_t type) {
+  DP("__tgt_push_mapper_component(Handle=" DPxMOD
+     ") adds an entry (Base=" DPxMOD ", Begin=" DPxMOD ", Size=%" PRId64
+     ", Type=0x%" PRIx64 ").\n",
+     DPxPTR(rt_mapper_handle), DPxPTR(base), DPxPTR(begin), size, type);
+  auto *MapperComponentsPtr = (struct MapperComponentsTy *)rt_mapper_handle;
+  MapperComponentsPtr->Components.push_back(
+      MapComponentInfoTy(base, begin, size, type));
+}
+
 EXTERN void __kmpc_push_target_tripcount(int64_t device_id,
     uint64_t loop_tripcount) {
   if (IsOffloadDisabled())

openmp/libomptarget/src/private.h

@@ -41,6 +41,24 @@ enum kmp_target_offload_kind {
 typedef enum kmp_target_offload_kind kmp_target_offload_kind_t;
 extern kmp_target_offload_kind_t TargetOffloadPolicy;
 
+// This structure stores information of a mapped memory region.
+struct MapComponentInfoTy {
+  void *Base;
+  void *Begin;
+  int64_t Size;
+  int64_t Type;
+  MapComponentInfoTy() = default;
+  MapComponentInfoTy(void *Base, void *Begin, int64_t Size, int64_t Type)
+      : Base(Base), Begin(Begin), Size(Size), Type(Type) {}
+};
+
+// This structure stores all components of a user-defined mapper. The number of
+// components are dynamically decided, so we utilize C++ STL vector
+// implementation here.
+struct MapperComponentsTy {
+  std::vector<MapComponentInfoTy> Components;
+};
+
 ////////////////////////////////////////////////////////////////////////////////
 // implemtation for fatal messages
 ////////////////////////////////////////////////////////////////////////////////

openmp/libomptarget/test/mapping/declare_mapper_api.cpp

@@ -0,0 +1,46 @@
+// RUN: %libomptarget-compile-run-and-check-aarch64-unknown-linux-gnu
+// RUN: %libomptarget-compile-run-and-check-powerpc64-ibm-linux-gnu
+// RUN: %libomptarget-compile-run-and-check-powerpc64le-ibm-linux-gnu
+// RUN: %libomptarget-compile-run-and-check-x86_64-pc-linux-gnu
+
+#include <cstdio>
+#include <cstdlib>
+
+// Data structure definitions copied from OpenMP RTL.
+struct MapComponentInfoTy {
+  void *Base;
+  void *Begin;
+  int64_t Size;
+  int64_t Type;
+  MapComponentInfoTy() = default;
+  MapComponentInfoTy(void *Base, void *Begin, int64_t Size, int64_t Type)
+      : Base(Base), Begin(Begin), Size(Size), Type(Type) {}
+};
+
+struct MapperComponentsTy {
+  std::vector<MapComponentInfoTy> Components;
+};
+
+// OpenMP RTL interfaces
+#ifdef __cplusplus
+extern "C" {
+#endif
+int64_t __tgt_mapper_num_components(void *rt_mapper_handle);
+void __tgt_push_mapper_component(void *rt_mapper_handle, void *base,
+                                 void *begin, int64_t size, int64_t type);
+#ifdef __cplusplus
+}
+#endif
+
+int main(int argc, char *argv[]) {
+  MapperComponentsTy MC;
+  void *base, *begin;
+  int64_t size, type;
+  // Push 2 elements into MC.
+  __tgt_push_mapper_component((void *)&MC, base, begin, size, type);
+  __tgt_push_mapper_component((void *)&MC, base, begin, size, type);
+  int64_t num = __tgt_mapper_num_components((void *)&MC);
+  // CHECK: num=2
+  printf("num=%lld\n", num);
+  return 0;
+}