[clang] [llvm] [SYCL] Add offload wrapping for SYCL kind. (PR #147508)

[Nick Sarnie via llvm-commits]

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@@ -620,6 +635,410 @@ void createRegisterFatbinFunction(Module &M, GlobalVariable *FatbinDesc,
   // Add this function to constructors.
   appendToGlobalCtors(M, CtorFunc, /*Priority=*/101);
 }
+
+/// SYCLWrapper helper class that creates all LLVM IRs wrapping given images.
+struct SYCLWrapper {
+  Module &M;
+  LLVMContext &C;
+  SYCLJITOptions Options;
+
+  StructType *EntryTy = nullptr;
+  StructType *SyclDeviceImageTy = nullptr;
+  StructType *SyclBinDescTy = nullptr;
+
+  SYCLWrapper(Module &M, const SYCLJITOptions &Options)
+      : M(M), C(M.getContext()), Options(Options) {
+    EntryTy = offloading::getEntryTy(M);
+    SyclDeviceImageTy = getSyclDeviceImageTy();
+    SyclBinDescTy = getSyclBinDescTy();
+  }
+
+  IntegerType *getSizeTTy() {
+    switch (M.getDataLayout().getPointerSize()) {
+    case 4:
+      return Type::getInt32Ty(C);
+    case 8:
+      return Type::getInt64Ty(C);
+    }
+    llvm_unreachable("unsupported pointer type size");
+  }
+
+  SmallVector<Constant *, 2> getSizetConstPair(size_t First, size_t Second) {
+    IntegerType *SizeTTy = getSizeTTy();
+    return SmallVector<Constant *, 2>{ConstantInt::get(SizeTTy, First),
+                                      ConstantInt::get(SizeTTy, Second)};
+  }
+
+  /// Note: Properties aren't supported and the support is going
+  /// to be added later.
+  /// Creates a structure corresponding to:
+  /// SYCL specific image descriptor type.
+  /// \code
+  /// struct __sycl.tgt_device_image {
+  ///   // version of this structure - for backward compatibility;
+  ///   // all modifications which change order/type/offsets of existing fields
+  ///   // should increment the version.
+  ///   uint16_t Version;
+  ///   // the kind of offload model the image employs.
+  ///   uint8_t OffloadKind;
+  ///   // format of the image data - SPIRV, LLVMIR bitcode, etc
+  ///   uint8_t Format;
+  ///   // null-terminated string representation of the device's target
+  ///   // architecture
+  ///   const char *Arch;
+  ///   // a null-terminated string; target- and compiler-specific options
+  ///   // which are suggested to use to "compile" program at runtime
+  ///   const char *CompileOptions;
+  ///   // a null-terminated string; target- and compiler-specific options
+  ///   // which are suggested to use to "link" program at runtime
+  ///   const char *LinkOptions;
+  ///   // Pointer to the device binary image start
+  ///   void *ImageStart;
+  ///   // Pointer to the device binary image end
+  ///   void *ImageEnd;
+  ///   // the entry table
+  ///   __tgt_offload_entry *EntriesBegin;
+  ///   __tgt_offload_entry *EntriesEnd;
+  ///   const char *PropertiesBegin;
+  ///   const char *PropertiesEnd;
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sarnex wrote:

i dont really understand why these are `const char*` but i think we are planning to rework these anyway so i guess it doesnt matter

https://github.com/llvm/llvm-project/pull/147508