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

[Alexey Sachkov via llvm-commits]

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@@ -0,0 +1,189 @@
+//===--- 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
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include <level_zero/ze_api.h>
+
+#include "Shared/EnvironmentVar.h"
+
+#include "L0Defs.h"
+
+namespace llvm::omp::target::plugin {
+/// Command submission mode
+enum class CommandModeTy { Sync = 0, Async, AsyncOrdered };
+
+/// Specialization constants used for a module compilation.
+class SpecConstantsTy {
+  std::vector<uint32_t> ConstantIds;
+  std::vector<const void *> ConstantValues;
+
+public:
+  SpecConstantsTy() = default;
+  SpecConstantsTy(const SpecConstantsTy &) = delete;
+  SpecConstantsTy(SpecConstantsTy &&) = delete;
+  SpecConstantsTy &operator=(const SpecConstantsTy &) = delete;
+  SpecConstantsTy &operator=(const SpecConstantsTy &&) = delete;
+  SpecConstantsTy(const SpecConstantsTy &&Other)
+      : ConstantIds(std::move(Other.ConstantIds)),
+        ConstantValues(std::move(Other.ConstantValues)) {}
+
+  ~SpecConstantsTy() {
+    for (auto I : ConstantValues) {
+      const char *ValuePtr = reinterpret_cast<const char *>(I);
+      delete[] ValuePtr;
+    }
+  }
+
+  template <typename T> void addConstant(uint32_t Id, T Val) {
+    const size_t ValSize = sizeof(Val);
+    char *ValuePtr = new char[ValSize];
+    *reinterpret_cast<T *>(ValuePtr) = Val;
+
+    ConstantIds.push_back(Id);
+    ConstantValues.push_back(reinterpret_cast<void *>(ValuePtr));
+  }
+
+  ze_module_constants_t getModuleConstants() const {
+    ze_module_constants_t Tmp{static_cast<uint32_t>(ConstantValues.size()),
+                              ConstantIds.data(),
+                              // Unfortunately we have to const_cast it.
+                              // L0 data type should probably be fixed.
+                              const_cast<const void **>(ConstantValues.data())};
+    return Tmp;
+  }
+};
+#define FIXED static constexpr
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AlexeySachkov wrote:

That is a weird naming choice I would say, is it an artifact from some earlier bugfix? Can it be inlined?

Oh, looking at the code below one more time, I guess the intent was to say "this is a constant", but in less words. To me, that is not worth the macro

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