1 files changed, 107 insertions, 0 deletions
diff --git a/offload/DeviceRTL/src/Tasking.cpp b/offload/DeviceRTL/src/Tasking.cpp
new file mode 100644
index 000000000000..2dc33562e6d7
--- /dev/null
+++ b/offload/DeviceRTL/src/Tasking.cpp
@@ -0,0 +1,107 @@
+//===-------- Tasking.cpp - NVPTX OpenMP tasks support ------------ C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Task implementation support.
+//
+// TODO: We should not allocate and execute the task in two steps. A new API is
+//       needed for that though.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Interface.h"
+#include "State.h"
+#include "Types.h"
+#include "Utils.h"
+
+using namespace ompx;
+
+#pragma omp begin declare target device_type(nohost)
+
+extern "C" {
+
+TaskDescriptorTy *__kmpc_omp_task_alloc(IdentTy *, int32_t, int32_t,
+                                        size_t TaskSizeInclPrivateValues,
+                                        size_t SharedValuesSize,
+                                        TaskFnTy TaskFn) {
+  auto TaskSizeInclPrivateValuesPadded =
+      utils::roundUp(TaskSizeInclPrivateValues, uint64_t(sizeof(void *)));
+  auto TaskSizeTotal = TaskSizeInclPrivateValuesPadded + SharedValuesSize;
+  TaskDescriptorTy *TaskDescriptor = (TaskDescriptorTy *)memory::allocGlobal(
+      TaskSizeTotal, "explicit task descriptor");
+  TaskDescriptor->Payload =
+      utils::advance(TaskDescriptor, TaskSizeInclPrivateValuesPadded);
+  TaskDescriptor->TaskFn = TaskFn;
+
+  return TaskDescriptor;
+}
+
+int32_t __kmpc_omp_task(IdentTy *Loc, uint32_t TId,
+                        TaskDescriptorTy *TaskDescriptor) {
+  return __kmpc_omp_task_with_deps(Loc, TId, TaskDescriptor, 0, 0, 0, 0);
+}
+
+int32_t __kmpc_omp_task_with_deps(IdentTy *Loc, uint32_t TId,
+                                  TaskDescriptorTy *TaskDescriptor, int32_t,
+                                  void *, int32_t, void *) {
+  state::DateEnvironmentRAII DERAII(Loc);
+
+  TaskDescriptor->TaskFn(0, TaskDescriptor);
+
+  memory::freeGlobal(TaskDescriptor, "explicit task descriptor");
+  return 0;
+}
+
+void __kmpc_omp_task_begin_if0(IdentTy *Loc, uint32_t TId,
+                               TaskDescriptorTy *TaskDescriptor) {
+  state::enterDataEnvironment(Loc);
+}
+
+void __kmpc_omp_task_complete_if0(IdentTy *Loc, uint32_t TId,
+                                  TaskDescriptorTy *TaskDescriptor) {
+  state::exitDataEnvironment();
+
+  memory::freeGlobal(TaskDescriptor, "explicit task descriptor");
+}
+
+void __kmpc_omp_wait_deps(IdentTy *Loc, uint32_t TId, int32_t, void *, int32_t,
+                          void *) {}
+
+void __kmpc_taskgroup(IdentTy *Loc, uint32_t TId) {}
+
+void __kmpc_end_taskgroup(IdentTy *Loc, uint32_t TId) {}
+
+int32_t __kmpc_omp_taskyield(IdentTy *Loc, uint32_t TId, int) { return 0; }
+
+int32_t __kmpc_omp_taskwait(IdentTy *Loc, uint32_t TId) { return 0; }
+
+void __kmpc_taskloop(IdentTy *Loc, uint32_t TId,
+                     TaskDescriptorTy *TaskDescriptor, int,
+                     uint64_t *LowerBound, uint64_t *UpperBound, int64_t, int,
+                     int32_t, uint64_t, void *) {
+  // Skip task entirely if empty iteration space.
+  if (*LowerBound > *UpperBound)
+    return;
+
+  // The compiler has already stored lb and ub in the TaskDescriptorTy structure
+  // as we are using a single task to execute the entire loop, we can leave
+  // the initial task_t untouched
+  __kmpc_omp_task_with_deps(Loc, TId, TaskDescriptor, 0, 0, 0, 0);
+}
+
+int omp_in_final(void) {
+  // treat all tasks as final... Specs may expect runtime to keep
+  // track more precisely if a task was actively set by users... This
+  // is not explicitly specified; will treat as if runtime can
+  // actively decide to put a non-final task into a final one.
+  return 1;
+}
+
+int omp_get_max_task_priority(void) { return 0; }
+}
+
+#pragma omp end declare target