[clang] [Clang] Make `-Xarch_` handling generic for all toolchains (PR #125421)

[Artem Belevich via cfe-commits]

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+// RUN: %clang -x cuda %s -Xarch_nvptx64 -O3 -S -nogpulib -nogpuinc -### 2>&1 | FileCheck -check-prefix=O3ONCE %s
+// RUN: %clang -x cuda %s -Xarch_device -O3 -S -nogpulib -nogpuinc -### 2>&1 | FileCheck -check-prefix=O3ONCE %s
+// RUN: %clang -x hip %s -Xarch_amdgcn -O3 -S -nogpulib -nogpuinc -### 2>&1 | FileCheck -check-prefix=O3ONCE %s
+// RUN: %clang -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -nogpulib -nogpuinc \
+// RUN:   -Xarch_amdgcn -march=gfx90a -Xarch_amdgcn -O3 -S -### %s 2>&1 \
+// RUN: | FileCheck -check-prefix=O3ONCE %s
+// RUN: %clang -fopenmp -fopenmp-targets=nvptx64-nvidia-cuda -nogpulib -nogpuinc \
+// RUN:   -Xarch_nvptx64 -march=sm_52 -Xarch_nvptx64 -O3 -S -### %s 2>&1 \
+// RUN: | FileCheck -check-prefix=O3ONCE %s
+// O3ONCE: "-O3"
+// O3ONCE-NOT: "-O3"
+
+// RUN: %clang -fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda,amdgcn-amd-amdhsa -nogpulib \
+// RUN:   --target=x86_64-unknown-linux-gnu -Xarch_nvptx64 --offload-arch=sm_52,sm_60 -nogpuinc \
+// RUN:   -Xarch_amdgcn --offload-arch=gfx90a,gfx1030 -ccc-print-bindings -### %s 2>&1 \
+// RUN: | FileCheck -check-prefix=OPENMP %s
+//
+// OPENMP: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[INPUT:.+]]"], output: "[[HOST_BC:.+]]"
+// OPENMP: # "amdgcn-amd-amdhsa" - "clang", inputs: ["[[INPUT]]", "[[HOST_BC]]"], output: "[[GFX1030_BC:.+]]"
+// OPENMP: # "amdgcn-amd-amdhsa" - "clang", inputs: ["[[INPUT]]", "[[HOST_BC]]"], output: "[[GFX90A_BC:.+]]"
+// OPENMP: # "nvptx64-nvidia-cuda" - "clang", inputs: ["[[INPUT]]", "[[HOST_BC]]"], output: "[[SM52_PTX:.+]]"
+// OPENMP: # "nvptx64-nvidia-cuda" - "NVPTX::Assembler", inputs: ["[[SM52_PTX]]"], output: "[[SM52_CUBIN:.+]]"
+// OPENMP: # "nvptx64-nvidia-cuda" - "clang", inputs: ["[[INPUT]]", "[[HOST_BC]]"], output: "[[SM60_PTX:.+]]"
+// OPENMP: # "nvptx64-nvidia-cuda" - "NVPTX::Assembler", inputs: ["[[SM60_PTX]]"], output: "[[SM60_CUBIN:.+]]"
+// OPENMP: # "x86_64-unknown-linux-gnu" - "Offload::Packager", inputs: ["[[GFX1030_BC]]", "[[GFX90A_BC]]", "[[SM52_CUBIN]]", "[[SM60_CUBIN]]"], output: "[[BINARY:.+]]"
+// OPENMP: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[HOST_BC]]", "[[BINARY]]"], output: "[[HOST_OBJ:.+]]"
+// OPENMP: # "x86_64-unknown-linux-gnu" - "Offload::Linker", inputs: ["[[HOST_OBJ]]"], output: "a.out"
+
+// RUN: %clang -x cuda %s --offload-arch=sm_52,sm_60 -Xarch_sm_52 -O3 -Xarch_sm_60 -O0 \
+// RUN:   --target=x86_64-unknown-linux-gnu -Xarch_host -O3 -S -nogpulib -nogpuinc -### 2>&1 \
+// RUN: | FileCheck -check-prefix=CUDA %s
+// CUDA: "-cc1" "-triple" "nvptx64-nvidia-cuda" {{.*}}"-target-cpu" "sm_52" {{.*}}"-O3"
+// CUDA: "-cc1" "-triple" "nvptx64-nvidia-cuda" {{.*}}"-target-cpu" "sm_60" {{.*}}"-O0"
+// CUDA: "-cc1" "-triple" "x86_64-unknown-linux-gnu" {{.*}}"-O3"
+
+// RUN: %clang -x cuda %s -fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda \
+// RUN:   -Xarch_sm_52 --offload-arch=sm_52 -S -nogpulib -nogpuinc -### 2>&1 \
+// RUN: | FileCheck -check-prefix=SPECIFIC %s
+// SPECIFIC: "-cc1" "-triple" "nvptx64-nvidia-cuda" {{.*}}"-target-cpu" "sm_52"
----------------
Artem-B wrote:

IMO this special case makes no sense.

If I were to look at this command line in real life, my assumption would be that a user made a mistake and intended to write `--offload-arch=sm_52 -Xarch_sm_52 -some-option`. I.e. they targeted sm_52, and then wanted to tweak that compilation. In this case we effectively ignoring `-Xarch_sm_52` which was very likely *not* the user's intent.

`cc1` reporting an error when it got `--offload-arch` would be a better approach IMO, giving the feedback that the user is doing something wrong.

On the other hand you've mentioned that:
> using -Xarch_amdgcn --offload-arch=gfx1030 is very meaningful for OpenMP where the user can enable multiple toolchains at the same time.

So, it looks like handling of these options is also language-dependent. For CUDA, blindly passing Xarch* options down to the compilation selected by Xarch kind (back-end, or specific GPU) and letting cc1 deal with those options would probably be acceptable.

The same approach may also work for OpenMP, where cc1 can do something sensible with --offload-arch passed to it and does not have to error out.



https://github.com/llvm/llvm-project/pull/125421