[llvm] [OFFLOAD] Add plugin with support for Intel oneAPI Level Zero (PR #158900)

[Joseph Huber via llvm-commits]

================
@@ -0,0 +1,77 @@
+//===--- Level Zero Target RTL Implementation -----------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// External and other auxilary definitions
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef OPENMP_LIBOMPTARGET_PLUGINS_NEXTGEN_LEVEL_ZERO_L0DEFS_H
+#define OPENMP_LIBOMPTARGET_PLUGINS_NEXTGEN_LEVEL_ZERO_L0DEFS_H
+
+#include "PluginInterface.h"
+#include "Shared/Requirements.h"
+#include "omptarget.h"
+
+#define LIBOMP_DECL(RetType, FnDecl) RetType __cdecl FnDecl
+
+enum class AllocOptionTy : int32_t {
+  ALLOC_OPT_NONE = 0,
+  ALLOC_OPT_REDUCTION_SCRATCH = 1,
+  ALLOC_OPT_REDUCTION_COUNTER = 2,
+  ALLOC_OPT_HOST_MEM = 3,
+  ALLOC_OPT_SLM = 4,
+};
+
+/// Host runtime routines being used
+extern "C" {
+LIBOMP_DECL(int, omp_get_max_teams(void));
----------------
jhuber6 wrote:

This is very strange, does LevelZero use host OpenMP for threading or something? Why does this need to live at the plugin level and not the `libomptarget` level?

https://github.com/llvm/llvm-project/pull/158900