[clang] [Clang][NFC] Clean up OpenMP offload toolchain generation (PR #145549)

[Shilei Tian via cfe-commits]

================
@@ -1044,82 +1040,78 @@ void Driver::CreateOffloadingDeviceToolChains(Compilation &C,
             << OpenMPTargets->getAsString(C.getInputArgs());
         return;
       }
+
+      // Make sure these show up in a deterministic order.
+      std::multiset<StringRef> OpenMPTriples;
       for (StringRef T : OpenMPTargets->getValues())
         OpenMPTriples.insert(T);
+
+      llvm::StringMap<StringRef> FoundNormalizedTriples;
+      for (StringRef T : OpenMPTriples) {
+        llvm::Triple TT(ToolChain::getOpenMPTriple(T));
+        std::string NormalizedName = TT.normalize();
+
+        // Make sure we don't have a duplicate triple.
+        auto [TripleIt, Inserted] =
+            FoundNormalizedTriples.try_emplace(NormalizedName, T);
+        if (!Inserted) {
+          Diag(clang::diag::warn_drv_omp_offload_target_duplicate)
+              << T << TripleIt->second;
+          continue;
+        }
+
+        // If the specified target is invalid, emit a diagnostic.
+        if (TT.getArch() == llvm::Triple::UnknownArch) {
+          Diag(clang::diag::err_drv_invalid_omp_target) << T;
+          continue;
+        }
+
+        auto &TC = getOffloadToolChain(C.getInputArgs(), Action::OFK_OpenMP, TT,
+                                       C.getDefaultToolChain().getTriple());
+        C.addOffloadDeviceToolChain(&TC, Action::OFK_OpenMP);
+      }
     } else if (C.getInputArgs().hasArg(options::OPT_offload_arch_EQ) &&
                ((!IsHIP && !IsCuda) || UseLLVMOffload)) {
-      const ToolChain *HostTC = C.getSingleOffloadToolChain<Action::OFK_Host>();
-      auto AMDTriple = getHIPOffloadTargetTriple(*this, C.getInputArgs());
-      auto NVPTXTriple = getNVIDIAOffloadTargetTriple(*this, C.getInputArgs(),
-                                                      HostTC->getTriple());
+      llvm::Triple AMDTriple("amdgcn-amd-amdhsa");
+      llvm::Triple NVPTXTriple("nvptx64-nvidia-cuda");
 
       // Attempt to deduce the offloading triple from the set of architectures.
       // We can only correctly deduce NVPTX / AMDGPU triples currently.
-      // We need to temporarily create these toolchains so that we can access
-      // tools for inferring architectures.
-      llvm::DenseSet<StringRef> Archs;
-      for (const std::optional<llvm::Triple> &TT : {NVPTXTriple, AMDTriple}) {
-        if (!TT)
-          continue;
-
-        auto &TC =
-            getOffloadToolChain(C.getInputArgs(), Action::OFK_OpenMP, *TT,
-                                C.getDefaultToolChain().getTriple());
-        for (StringRef Arch :
-             getOffloadArchs(C, C.getArgs(), Action::OFK_OpenMP, &TC, true))
-          Archs.insert(Arch);
-      }
+      for (const llvm::Triple &TT : {AMDTriple, NVPTXTriple}) {
+        auto &TC = getOffloadToolChain(C.getInputArgs(), Action::OFK_OpenMP, TT,
+                                       C.getDefaultToolChain().getTriple());
+
+        llvm::DenseSet<StringRef> Archs =
+            getOffloadArchs(C, C.getArgs(), Action::OFK_OpenMP, &TC, true);
+        llvm::DenseSet<StringRef> ArchsForTarget;
+        for (StringRef Arch : Archs) {
+          bool IsNVPTX = IsNVIDIAOffloadArch(
+              StringToOffloadArch(getProcessorFromTargetID(NVPTXTriple, Arch)));
+          bool IsAMDGPU = IsAMDOffloadArch(
+              StringToOffloadArch(getProcessorFromTargetID(AMDTriple, Arch)));
+          if (!IsNVPTX && !IsAMDGPU && !Arch.equals_insensitive("native")) {
+            Diag(clang::diag::err_drv_failed_to_deduce_target_from_arch)
+                << Arch;
+            return;
+          }
 
-      for (StringRef Arch : Archs) {
-        if (NVPTXTriple && IsNVIDIAOffloadArch(StringToOffloadArch(
-                               getProcessorFromTargetID(*NVPTXTriple, Arch)))) {
-          DerivedArchs[NVPTXTriple->getTriple()].insert(Arch);
-        } else if (AMDTriple &&
-                   IsAMDOffloadArch(StringToOffloadArch(
-                       getProcessorFromTargetID(*AMDTriple, Arch)))) {
-          DerivedArchs[AMDTriple->getTriple()].insert(Arch);
-        } else {
-          Diag(clang::diag::err_drv_failed_to_deduce_target_from_arch) << Arch;
-          return;
+          if (TT.isNVPTX() && IsNVPTX) {
+            ArchsForTarget.insert(Arch);
+          } else if (TT.isAMDGPU() && IsAMDGPU) {
+            ArchsForTarget.insert(Arch);
+          }
----------------
shiltian wrote:

```suggestion
          if (TT.isNVPTX() && IsNVPTX)
            ArchsForTarget.insert(Arch);
          else if (TT.isAMDGPU() && IsAMDGPU)
            ArchsForTarget.insert(Arch);
```

https://github.com/llvm/llvm-project/pull/145549