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

[Alex Duran via llvm-commits]

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@@ -0,0 +1,371 @@
+//===--- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Level Zero RTL Options support
+//
+//===----------------------------------------------------------------------===//
+
+#include "omptarget.h"
+
+#include "L0Defs.h"
+#include "L0Options.h"
+#include "L0Trace.h"
+
+namespace llvm::omp::target::plugin {
+
+/// Is the given RootID, SubID, CcsID specified in ONEAPI_DEVICE_SELECTOR
+bool L0OptionsTy::shouldAddDevice(int32_t RootID, int32_t SubID,
+                                  int32_t CCSID) const {
+  if (ExplicitRootDevices.empty())
+    return false;
+  for (const auto &RootDev : ExplicitRootDevices) {
+    const auto ErootID = std::get<1>(RootDev);
+    if (ErootID != -2 && RootID != ErootID)
+      continue;
+    const auto EsubID = std::get<2>(RootDev);
+    if (((EsubID != -2) || (SubID == -1)) && (EsubID != SubID))
+      continue;
+    const auto ECCSID = std::get<3>(RootDev);
+    if (((ECCSID != -2) || (CCSID == -1)) && (ECCSID != CCSID))
+      continue;
+    // Check if isDiscard
+    if (!std::get<0>(RootDev))
+      return false;
+    return true;
+  }
+  return false;
+}
+
+/// Read environment variables
+void L0OptionsTy::processEnvironmentVars() {
+  // Compilation options for IGC
+  UserCompilationOptions +=
+      std::string(" ") +
+      StringEnvar("LIBOMPTARGET_LEVEL_ZERO_COMPILATION_OPTIONS", "").get();
+
+  // Explicit Device mode if ONEAPI_DEVICE_SELECTOR is set
+  const StringEnvar DeviceSelectorVar("ONEAPI_DEVICE_SELECTOR", "");
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adurang wrote:

I've removed this for the time being. I agree it probably makes more sense to move it elsewhere.

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