[SYCL][Driver][HIP] Do not define __CUDA_ARCH__ for HIP-AMD targets (#15443)

Fixes: #15544

Author: Georgi Mirazchiyski

clang/lib/Basic/Targets/AMDGPU.cpp

@@ -309,7 +309,6 @@ void AMDGPUTargetInfo::getTargetDefines(const LangOptions &Opts,
                         Twine("\"") + Twine(CanonName) + Twine("\""));
     Builder.defineMacro("__amdgcn_target_id__",
                         Twine("\"") + Twine(*getTargetID()) + Twine("\""));
-    Builder.defineMacro("__CUDA_ARCH__", "0");
     for (auto F : getAllPossibleTargetIDFeatures(getTriple(), CanonName)) {
       auto Loc = OffloadArchFeatures.find(F);
       if (Loc != OffloadArchFeatures.end()) {

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__");
   }
 

clang/test/Driver/sycl-cuda-arch-macro.cpp

@@ -1,9 +1,13 @@
 // Verify the __CUDA_ARCH__ macro has not been defined when offloading SYCL on NVPTX
 // RUN: %clangxx -E -dM -fsycl -fsycl-targets=nvptx64-nvidia-cuda -Xsycl-target-backend --offload-arch=sm_80 -nocudalib -fno-sycl-libspirv %s 2>&1 \
 // RUN: | FileCheck --check-prefix=CHECK-CUDA-ARCH-MACRO %s
+// Verify the __CUDA_ARCH__ macro has not been defined when offloading SYCL on AMDGPU
+// RUN: %clangxx -E -dM -fsycl -fsycl-targets=amdgcn-amd-amdhsa -Xsycl-target-backend --offload-arch=gfx90a -nogpulib -fno-sycl-libspirv %s 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-CUDA-ARCH-MACRO %s
 // CHECK-CUDA-ARCH-MACRO-NOT: #define __CUDA_ARCH__ {{[0-9]+}}
 
 // Verify that '-fcuda-is-device' is not supplied when offloading SYCL on NVPTX
+// NOTE: AMDGPU targets, i.e. "amdgcn-amd-amdhsa" may rely on "fcuda-is-device"
 // RUN: %clangxx -### -fsycl -fsycl-targets=nvptx64-nvidia-cuda -Xsycl-target-backend --offload-arch=sm_80 -nocudalib -fno-sycl-libspirv %s 2>&1 \
 // RUN: | FileCheck --check-prefix=CHECK-CUDA-IS-DEVICE %s
 // CHECK-CUDA-IS-DEVICE: clang{{.*}} "-cc1" "-triple" "nvptx64-nvidia-cuda"

clang/test/Preprocessor/sycl-macro.cpp

@@ -36,6 +36,6 @@
 // CHECK-CUDA:#define __SYCL_CUDA_ARCH__ [[ARCH_CODE]]
 // CHECK-CUDA-NOT:#define __CUDA_ARCH__ {{[0-9]+}}
 
-// CHECK-HIP:#define __CUDA_ARCH__ 0
+// CHECK-HIP-NOT:#define __CUDA_ARCH__ {{[0-9]+}}
 
 // CHECK-CUDA-FEATURE:#define __CUDA_ARCH_FEAT_SM90_ALL 1