[SYCL] Disable dereferenceable attribute for SPIRV emitted from SYCL …

…1.2.1.

Signed-off-by: Vladimir Lazarev <vladimir.lazarev@intel.com>

clang/lib/CodeGen/BackendUtil.cpp

@@ -63,6 +63,11 @@
 #include "llvm/Transforms/Utils/SymbolRewriter.h"
 #include "LLVMSPIRVLib.h"
 #include <memory>
+
+namespace SPIRV {
+  extern llvm::cl::opt<bool> SPIRVNoDerefAttr;
+}
+
 using namespace clang;
 using namespace llvm;
 
@@ -835,7 +840,8 @@ void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
 
 
   case Backend_EmitSPIRV:
-
+    if (LangOpts.SYCL)
+      SPIRV::SPIRVNoDerefAttr = true;
     PerModulePasses.add(createSPIRVWriterPass(*OS));
 
     break;

clang/test/CodeGenSYCL/spir-no-deref-attr.cpp

@@ -0,0 +1,20 @@
+// RUN: %clang -cc1 -triple spir64-unknown-linux-sycldevice -std=c++11 -fsycl-is-device -S -emit-spirv -x c++ %s -o %t.spv
+// RUN: llvm-spirv %t.spv -to-text -o %t.txt
+// RUN: FileCheck < %t.txt %s --check-prefix=CHECK
+
+template <typename name, typename Func>
+__attribute__((sycl_kernel)) void kernel_single_task(Func kernelFunc) {
+  kernelFunc();
+}
+struct foo {
+  static void bar(int &val) {
+    val = 1;
+  }
+};
+int main() {
+  kernel_single_task<class fake_kernel>([]() { int var; foo::bar(var); });
+  return 0;
+}
+
+// CHECK: 3 Name [[os_ID:[0-9]+]] "val"
+// CHECK-NOT: Decorate {{[0-9]+}} MaxByteOffset