[llvm] [offload][SYCL] Add Module splitting by categories. (PR #131347)

[Maksim Sabianin via llvm-commits]

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@@ -0,0 +1,101 @@
+//===------------ SYCLUtils.h - SYCL utility functions --------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+// Utility functions for SYCL.
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_FRONTEND_SYCL_UTILS_H
+#define LLVM_FRONTEND_SYCL_UTILS_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
+
+#include <optional>
+#include <string>
+
+namespace llvm {
+
+class Module;
+class Function;
+class raw_ostream;
+
+namespace sycl {
+
+enum class IRSplitMode {
+  IRSM_PER_TU,     // one module per translation unit
+  IRSM_PER_KERNEL, // one module per kernel
+  IRSM_NONE        // no splitting
+};
+
+/// \returns IRSplitMode value if \p S is recognized. Otherwise, std::nullopt is
+/// returned.
+std::optional<IRSplitMode> convertStringToSplitMode(StringRef S);
+
+/// FunctionCategorizer used for splitting in SYCL compilation flow.
+class FunctionCategorizer {
+public:
+  FunctionCategorizer(IRSplitMode SM);
+
+  FunctionCategorizer() = delete;
+  FunctionCategorizer(FunctionCategorizer &) = delete;
+  FunctionCategorizer &operator=(const FunctionCategorizer &) = delete;
+  FunctionCategorizer(FunctionCategorizer &&) = default;
+  FunctionCategorizer &operator=(FunctionCategorizer &&) = default;
+
+  /// Returns integer specifying the category for the entry point.
+  /// If the given function isn't an entry point then returns std::nullopt.
+  std::optional<int> operator()(const Function &F);
+
+private:
+  struct KeyInfo {
+    static SmallString<0> getEmptyKey() { return SmallString<0>(""); }
+
+    static SmallString<0> getTombstoneKey() { return SmallString<0>("-"); }
+
+    static bool isEqual(const SmallString<0> &LHS, const SmallString<0> &RHS) {
+      return LHS == RHS;
+    }
+
+    static unsigned getHashValue(const SmallString<0> &S) {
+      return llvm::hash_value(StringRef(S));
+    }
+  };
+
+  IRSplitMode SM;
+  DenseMap<SmallString<0>, int, KeyInfo> StrKeyToID;
+};
+
+/// The structure represents a LLVM Module accompanied by additional
+/// information. Split Modules are being stored at disk due to the high RAM
+/// consumption during the whole splitting process.
+struct ModuleAndSYCLMetadata {
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maksimsab wrote:

Removed this structure at all.

https://github.com/llvm/llvm-project/pull/131347