Move the check for SYCL restricting adding CUDA_ARCH macro to the preprocessor

Author: Georgi Mirazchiyski

clang/lib/Driver/ToolChains/HIPAMD.cpp

@@ -283,10 +283,7 @@ void HIPAMDToolChain::addClangTargetOptions(
           DeviceOffloadingKind == Action::OFK_SYCL) &&
          "Only HIP and SYCL offloading kinds are supported for GPUs.");
 
-  // If we are compiling SYCL kernels for Nvidia GPUs throuh HIP, we do not
-  // support Cuda device code compatability, hence we do not allow Cuda mode.
-  if (getTriple().isNVPTX() && DeviceOffloadingKind != Action::OFK_SYCL)
-    CC1Args.push_back("-fcuda-is-device");
+  CC1Args.push_back("-fcuda-is-device");
 
   if (!DriverArgs.hasFlag(options::OPT_fgpu_rdc, options::OPT_fno_gpu_rdc,
                           false))

clang/lib/Frontend/InitPreprocessor.cpp

@@ -1491,9 +1491,10 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   }
 
   // CUDA device path compilaton
-  if (LangOpts.CUDAIsDevice && !LangOpts.HIP) {
+  if (LangOpts.CUDAIsDevice && !LangOpts.HIP && !LangOpts.isSYCL()) {
     // The CUDA_ARCH value is set for the GPU target specified in the NVPTX
     // backend's target defines.
+    // Note: SYCL targeting nvptx-cuda relies on __SYCL_CUDA_ARCH__ instead.
     Builder.defineMacro("__CUDA_ARCH__");
   }