[LIBOMPTARGET]Fix order of mapper data for targetDataEnd function.

targetDataMapper function fills arrays with the mapping data in the
direct order. When this function is called by targetDataBegin or
tgt_target_update functions, it works as expected. But targetDataEnd
function processes mapped data in reverse order. In this case, the base
pointer might be deleted before the associated data is deleted. Need to
reverse data, mapped by mapper, too, since it always adds data that must
be deleted at the end of the buffer.
Fixes the test declare_mapper_target_update.cpp.
Also, reduces the memry fragmentation by preallocation the memory
buffers.

Differential Revision: https://reviews.llvm.org/D85216

diff --git a/openmp/libomptarget/src/omptarget.cpp b/openmp/libomptarget/src/omptarget.cpp
index 5f8a3a6..4656ec0 100644 (file)
--- a/openmp/libomptarget/src/omptarget.cpp
+++ b/openmp/libomptarget/src/omptarget.cpp
@@ -230,22 +230,26 @@ int targetDataMapper(DeviceTy &Device, void *arg_base, void *arg,
   // Construct new arrays for args_base, args, arg_sizes and arg_types
   // using the information in MapperComponents and call the corresponding
   // target_data_* function using these new arrays.
-  std::vector<void *> mapper_args_base;
-  std::vector<void *> mapper_args;
-  std::vector<int64_t> mapper_arg_sizes;
-  std::vector<int64_t> mapper_arg_types;
-
-  for (auto& C : MapperComponents.Components) {
-    mapper_args_base.push_back(C.Base);
-    mapper_args.push_back(C.Begin);
-    mapper_arg_sizes.push_back(C.Size);
-    mapper_arg_types.push_back(C.Type);
+  std::vector<void *> MapperArgsBase(MapperComponents.Components.size());
+  std::vector<void *> MapperArgs(MapperComponents.Components.size());
+  std::vector<int64_t> MapperArgSizes(MapperComponents.Components.size());
+  std::vector<int64_t> MapperArgTypes(MapperComponents.Components.size());
+
+  for (unsigned I = 0, E = MapperComponents.Components.size(); I < E; ++I) {
+    auto &C =
+        MapperComponents
+            .Components[target_data_function == targetDataEnd ? I : E - I - 1];
+    MapperArgsBase[I] = C.Base;
+    MapperArgs[I] = C.Begin;
+    MapperArgSizes[I] = C.Size;
+    MapperArgTypes[I] = C.Type;
   }
 
   int rc = target_data_function(Device, MapperComponents.Components.size(),
-      mapper_args_base.data(), mapper_args.data(), mapper_arg_sizes.data(),
-      mapper_arg_types.data(), /*arg_mappers*/ nullptr,
-      /*__tgt_async_info*/ nullptr);
+                                MapperArgsBase.data(), MapperArgs.data(),
+                                MapperArgSizes.data(), MapperArgTypes.data(),
+                                /*arg_mappers*/ nullptr,
+                                /*__tgt_async_info*/ nullptr);
 
   return rc;
 }