[CUDA] Only allow NVIDIA offload-arch during CUDA compilation.

[tra]

Summary

Otherwise, if someone specifies a valid AMD arch, we may end up triggering an
assertion on unexpected arch later on.

Current tests didn't catch it because the failure does not get triggered with -###.

[yaxunl]

LGTM. Thanks.

[tra]

Ugh. I broke the cuda-bad-arch.cu test.

clang/test/Driver/cuda-bad-arch.cu

30

HIP tests should've used -x hip. I'll fix the test shortly.

[dyung]

I think your change also broke cuda-flush-denormals-to-zero.cu:

https://lab.llvm.org/buildbot/#/builders/139/builds/7048

[tra]

In D105295#2874935, @tra wrote:

Ugh. I broke the cuda-bad-arch.cu test.

Should be fixed in 25629bb45f0a4b8c8e99dbde4f4a7e3d980b9fd7

clang/lib/Driver/Driver.cpp

public:
     CudaActionBuilder(Compilation &C, DerivedArgList &Args,
                       const Driver::InputList &Inputs)
         : CudaActionBuilderBase(C, Args, Inputs, Action::OFK_Cuda) {
       DefaultCudaArch = CudaArch::SM_20;
     }
 
     StringRef getCanonicalOffloadArch(StringRef ArchStr) override {
       CudaArch Arch = StringToCudaArch(ArchStr);
-      if (Arch == CudaArch::UNKNOWN) {
+      if (Arch == CudaArch::UNKNOWN || !IsNVIDIAGpuArch(Arch)) {
         C.getDriver().Diag(clang::diag::err_drv_cuda_bad_gpu_arch) << ArchStr;
         return StringRef();
       }
       return CudaArchToString(Arch);
     }
 
     llvm::Optional<std::pair<llvm::StringRef, llvm::StringRef>>
     getConflictOffloadArchCombination(

clang/test/Driver/cuda-bad-arch.cu

 // Checks errors generated by passing a bad value for --cuda-gpu-arch.
 // REQUIRES: clang-driver
 // REQUIRES: x86-registered-target
 // REQUIRES: nvptx-registered-target
 // REQUIRES: amdgpu-registered-target
 
 // RUN: %clang -### -target x86_64-linux-gnu --cuda-gpu-arch=compute_20 -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix BAD %s
 // RUN: %clang -### -target x86_64-linux-gnu --cuda-gpu-arch=sm20 -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix BAD %s
 // RUN: %clang -### -target x86_64-linux-gnu --cuda-gpu-arch=sm_19 -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix BAD %s
+// RUN: %clang -### -target x86_64-linux-gnu --cuda-gpu-arch=gfx900 -c %s 2>&1 \
+// RUN: | FileCheck -check-prefix BAD %s
 
 // BAD: error: Unsupported CUDA gpu architecture
 
 // RUN: %clang -### -v --target=x86_64-linux-gnu --cuda-gpu-arch=sm_21 \
 // RUN:   --cuda-path=%S/Inputs/CUDA_90/usr/local/cuda %s 2>&1 \
 // RUN: | FileCheck -check-prefix BAD_CUDA9 %s
 
 // BAD_CUDA9: GPU arch sm_21 is supported by CUDA versions between 7.0 and 8.0
 
 // RUN: %clang -### -target x86_64-linux-gnu --cuda-gpu-arch=sm_20 -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix OK %s
 // RUN: %clang -### -target x86_64-linux-gnu --cuda-gpu-arch=sm_52 -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix OK %s
 // RUN: %clang -### -target x86_64-linux-gnu --cuda-gpu-arch=gfx908 -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix OK %s
 // RUN: %clang -### -target x86_64-linux-gnu --cuda-gpu-arch=gfx90a -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix OK %s
 // RUN: %clang -### -target x86_64-linux-gnu -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix OK %s
 
 // We don't allow using NVPTX/AMDGCN for host compilation.
 // RUN: %clang -### --cuda-host-only -target nvptx-nvidia-cuda -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix HOST_NVPTX %s
 // RUN: %clang -### --cuda-host-only -target amdgcn-amd-amdhsa -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix HOST_AMDGCN %s
 
 // OK-NOT: error: Unsupported CUDA gpu architecture
 // HOST_NVPTX: error: unsupported architecture 'nvptx' for host compilation.
 // HOST_AMDGCN: error: unsupported architecture 'amdgcn' for host compilation.