[OpenMP][NFC] Simplify identifying the device bitcode library

[jhuber6]

Summary

Now that the old device runtime has been deleted there is only a single
target that differs by the triple and the architecture. Simplify the
scheme for identifying the library but directly using the triple.

[JonChesterfield]

clang/lib/Driver/ToolChains/CommonArgs.cpp

2014–2016

ArchPrefix could be a const char* or stringref as before, one fewer malloc

clang/lib/Driver/ToolChains/AMDGPUOpenMP.cpp

void AMDGPUOpenMPToolChain::addClangTargetOptions(
 
   if (DriverArgs.hasArg(options::OPT_nogpulib))
     return;
 
   // Link the bitcode library late if we're using device LTO.
   if (getDriver().isUsingLTO(/* IsOffload */ true))
     return;
 
-  std::string BitcodeSuffix = "amdgpu-" + GPUArch;
-
-  addOpenMPDeviceRTL(getDriver(), DriverArgs, CC1Args, BitcodeSuffix,
-                     getTriple());
+  addOpenMPDeviceRTL(getDriver(), DriverArgs, CC1Args, GPUArch, getTriple());
 }
 
 llvm::opt::DerivedArgList *AMDGPUOpenMPToolChain::TranslateArgs(
     const llvm::opt::DerivedArgList &Args, StringRef BoundArch,
     Action::OffloadKind DeviceOffloadKind) const {
   DerivedArgList *DAL =
       HostTC.TranslateArgs(Args, BoundArch, DeviceOffloadKind);
   if (!DAL)

clang/lib/Driver/ToolChains/Clang.cpp

if (D.isUsingLTO(/* IsOffload */ true)) {
     // Pass in the bitcode library to be linked during LTO.
     for (auto &I :
          llvm::make_range(OpenMPTCRange.first, OpenMPTCRange.second)) {
       const ToolChain *TC = I.second;
       const Driver &TCDriver = TC->getDriver();
       const ArgList &TCArgs = C.getArgsForToolChain(TC, "", Action::OFK_OpenMP);
       StringRef Arch = TCArgs.getLastArgValue(options::OPT_march_EQ);
 
-      std::string BitcodeSuffix;
-      if (TC->getTriple().isNVPTX())
-        BitcodeSuffix += "nvptx-";
-      else if (TC->getTriple().isAMDGPU())
-        BitcodeSuffix += "amdgpu-";
-      BitcodeSuffix += Arch;
-
       ArgStringList BitcodeLibrary;
-      addOpenMPDeviceRTL(TCDriver, TCArgs, BitcodeLibrary, BitcodeSuffix,
+      addOpenMPDeviceRTL(TCDriver, TCArgs, BitcodeLibrary, Arch,
                          TC->getTriple());
 
       if (!BitcodeLibrary.empty())
         CmdArgs.push_back(
             Args.MakeArgString("-target-library=" + TC->getTripleString() +
                                "-" + Arch + "=" + BitcodeLibrary.back()));
     }
 

clang/lib/Driver/ToolChains/CommonArgs.cpp

if (LibPath) {
     for (StringRef Path : Frags)
       LibraryPaths.emplace_back(Path.trim());
   }
 
   OptSpecifier LibomptargetBCPathOpt =
       Triple.isAMDGCN() ? options::OPT_libomptarget_amdgpu_bc_path_EQ
                         : options::OPT_libomptarget_nvptx_bc_path_EQ;
 
-  StringRef ArchPrefix = Triple.isAMDGCN() ? "amdgcn" : "nvptx";
-  std::string LibOmpTargetName = "libomptarget-" + BitcodeSuffix.str() + ".bc";
+  StringRef ArchPrefix = Triple.isAMDGCN() ? "amdgpu" : "nvptx";
+  std::string LibOmpTargetName =
+      ("libomptarget-" + ArchPrefix + "-" + BitcodeSuffix + ".bc").str();
 
   // First check whether user specifies bc library
   if (const Arg *A = DriverArgs.getLastArg(LibomptargetBCPathOpt)) {
     SmallString<128> LibOmpTargetFile(A->getValue());
     if (llvm::sys::fs::exists(LibOmpTargetFile) &&
         llvm::sys::fs::is_directory(LibOmpTargetFile)) {
       llvm::sys::path::append(LibOmpTargetFile, LibOmpTargetName);
     }

clang/lib/Driver/ToolChains/Cuda.cpp

if (CudaInstallationVersion < CudaVersion::CUDA_92) {
           << CudaVersionToString(CudaInstallationVersion);
       return;
     }
 
     // Link the bitcode library late if we're using device LTO.
     if (getDriver().isUsingLTO(/* IsOffload */ true))
       return;
 
-    std::string BitcodeSuffix = "nvptx-" + GpuArch.str();
-
-    addOpenMPDeviceRTL(getDriver(), DriverArgs, CC1Args, BitcodeSuffix,
+    addOpenMPDeviceRTL(getDriver(), DriverArgs, CC1Args, GpuArch.str(),
                        getTriple());
     AddStaticDeviceLibsPostLinking(getDriver(), DriverArgs, CC1Args, "nvptx",
                                    GpuArch, /*isBitCodeSDL=*/true,
                                    /*postClangLink=*/true);
   }
 }
 
 llvm::DenormalMode CudaToolChain::getDefaultDenormalModeForType(