[clang] [llvm] [Offload][SYCL] Refactor OffloadKind implementation (PR #135809)

[Arvind Sudarsanam via cfe-commits]

https://github.com/asudarsa created https://github.com/llvm/llvm-project/pull/135809

Following are the changes:

1. Make OffloadKind enum values to be powers of two so we can use them like a bitfield
2. Include OFK_SYCL enum value
3. Modify ActiveOffloadKinds support in clang-linker-wrapper to use bitfields instead of a vector.

Thanks

>From ec072a0ef5b699c58dd2ac404c90a5078f4a774a Mon Sep 17 00:00:00 2001
From: Arvind Sudarsanam <arvind.sudarsanam at intel.com>
Date: Tue, 15 Apr 2025 09:27:27 -0700
Subject: [PATCH] [Offload][SYCL] Refactor OffloadKind implementation

Signed-off-by: Arvind Sudarsanam <arvind.sudarsanam at intel.com>
---
 .../tools/clang-linker-wrapper/ClangLinkerWrapper.cpp  | 10 ++++++----
 llvm/include/llvm/Object/OffloadBinary.h               | 10 ++++++----
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp b/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
index 52d922abbcaec..a76b6f1da1e1d 100644
--- a/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
+++ b/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
@@ -923,10 +923,9 @@ Expected<SmallVector<StringRef>> linkAndWrapDeviceFiles(
         });
     auto LinkerArgs = getLinkerArgs(Input, BaseArgs);
 
-    DenseSet<OffloadKind> ActiveOffloadKinds;
+    uint16_t ActiveOffloadKindMask = 0u;
     for (const auto &File : Input)
-      if (File.getBinary()->getOffloadKind() != OFK_None)
-        ActiveOffloadKinds.insert(File.getBinary()->getOffloadKind());
+      ActiveOffloadKindMask |= File.getBinary()->getOffloadKind();
 
     // Write any remaining device inputs to an output file.
     SmallVector<StringRef> InputFiles;
@@ -943,7 +942,10 @@ Expected<SmallVector<StringRef>> linkAndWrapDeviceFiles(
       return OutputOrErr.takeError();
 
     // Store the offloading image for each linked output file.
-    for (OffloadKind Kind : ActiveOffloadKinds) {
+    for (OffloadKind Kind = OFK_FIRST; Kind != OFK_LAST;
+         Kind = static_cast<OffloadKind>((uint16_t)(Kind) << 1)) {
+      if ((ActiveOffloadKindMask & Kind) == 0)
+        continue;
       llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> FileOrErr =
           llvm::MemoryBuffer::getFileOrSTDIN(*OutputOrErr);
       if (std::error_code EC = FileOrErr.getError()) {
diff --git a/llvm/include/llvm/Object/OffloadBinary.h b/llvm/include/llvm/Object/OffloadBinary.h
index c02aec8d956ed..858c7a59bce4a 100644
--- a/llvm/include/llvm/Object/OffloadBinary.h
+++ b/llvm/include/llvm/Object/OffloadBinary.h
@@ -32,10 +32,12 @@ namespace object {
 /// The producer of the associated offloading image.
 enum OffloadKind : uint16_t {
   OFK_None = 0,
-  OFK_OpenMP,
-  OFK_Cuda,
-  OFK_HIP,
-  OFK_LAST,
+  OFK_OpenMP = (1 << 1),
+  OFK_FIRST = OFK_OpenMP,
+  OFK_Cuda = (1 << 2),
+  OFK_HIP = (1 << 3),
+  OFK_SYCL = (1 << 4),
+  OFK_LAST = (1 << 5),
 };
 
 /// The type of contents the offloading image contains.