[Offload] Add support for loongarch64 to host plugin

This adds support for the loongarch64 architecture to the offload host
plugin.

Similar to #115773

To fix some test issues, I've had to add the LoongArch64 target to:

- CompilerInvocation::ParseLangArgs
- linkDevice in ClangLinuxWrapper.cpp
- OMPContext::OMPContext (to set the device_kind_cpu trait)

Reviewed By: jhuber6

Pull Request: #120173

Author: wangleiat

clang/lib/Frontend/CompilerInvocation.cpp

@@ -4257,6 +4257,7 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
       if (TT.getArch() == llvm::Triple::UnknownArch ||
           !(TT.getArch() == llvm::Triple::aarch64 || TT.isPPC() ||
             TT.getArch() == llvm::Triple::systemz ||
+            TT.getArch() == llvm::Triple::loongarch64 ||
             TT.getArch() == llvm::Triple::nvptx ||
             TT.getArch() == llvm::Triple::nvptx64 ||
             TT.getArch() == llvm::Triple::amdgcn ||

clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp

@@ -596,6 +596,7 @@ Expected<StringRef> linkDevice(ArrayRef<StringRef> InputFiles,
   case Triple::ppc64:
   case Triple::ppc64le:
   case Triple::systemz:
+  case Triple::loongarch64:
     return generic::clang(InputFiles, Args);
   default:
     return createStringError(Triple.getArchName() +

llvm/lib/Frontend/OpenMP/OMPContext.cpp

@@ -36,6 +36,7 @@ OMPContext::OMPContext(bool IsDeviceCompilation, Triple TargetTriple) {
   case Triple::aarch64:
   case Triple::aarch64_be:
   case Triple::aarch64_32:
+  case Triple::loongarch64:
   case Triple::mips:
   case Triple::mipsel:
   case Triple::mips64:

offload/CMakeLists.txt

@@ -207,6 +207,8 @@ set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} s390x-ibm-linux-gnu")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} s390x-ibm-linux-gnu-LTO")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} riscv64-unknown-linux-gnu")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} riscv64-unknown-linux-gnu-LTO")
+set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} loongarch64-unknown-linux-gnu")
+set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} loongarch64-unknown-linux-gnu-LTO")
 
 # Once the plugins for the different targets are validated, they will be added to
 # the list of supported targets in the current system.

offload/plugins-nextgen/common/src/Utils/ELF.cpp

@@ -47,6 +47,8 @@ uint16_t utils::elf::getTargetMachine() {
   return EM_PPC64;
 #elif defined(__riscv)
   return EM_RISCV;
+#elif defined(__loongarch__)
+  return EM_LOONGARCH;
 #else
 #warning "Unknown ELF compilation target architecture"
   return EM_NONE;

offload/plugins-nextgen/host/CMakeLists.txt

@@ -1,4 +1,4 @@
-set(supported_targets x86_64 aarch64 ppc64 ppc64le riscv64 s390x)
+set(supported_targets x86_64 aarch64 ppc64 ppc64le riscv64 s390x loongarch64)
 if(NOT ${CMAKE_SYSTEM_PROCESSOR} IN_LIST supported_targets)
   message(STATUS "Not building ${machine} NextGen offloading plugin")
   return()
@@ -63,4 +63,8 @@ elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "riscv64$")
   list(APPEND LIBOMPTARGET_SYSTEM_TARGETS
        "riscv64-unknown-linux-gnu" "riscv64-unknown-linux-gnu-LTO")
   set(LIBOMPTARGET_SYSTEM_TARGETS "${LIBOMPTARGET_SYSTEM_TARGETS}" PARENT_SCOPE)
+elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "loongarch64$")
+  list(APPEND LIBOMPTARGET_SYSTEM_TARGETS
+       "loongarch64-unknown-linux-gnu" "loongarch64-unknown-linux-gnu-LTO")
+  set(LIBOMPTARGET_SYSTEM_TARGETS "${LIBOMPTARGET_SYSTEM_TARGETS}" PARENT_SCOPE)
 endif()

offload/plugins-nextgen/host/dynamic_ffi/ffi.h

@@ -44,7 +44,7 @@ typedef enum ffi_abi {
 #if (defined(_M_X64) || defined(__x86_64__))
   FFI_DEFAULT_ABI = 2, // FFI_UNIX64.
 #elif defined(__aarch64__) || defined(__arm64__) || defined(_M_ARM64) ||       \
-    defined(__riscv)
+    defined(__riscv) || defined(__loongarch__)
   FFI_DEFAULT_ABI = 1, // FFI_SYSV.
 #elif defined(__powerpc64__)
   FFI_DEFAULT_ABI = 8, // FFI_LINUX.

offload/plugins-nextgen/host/src/rtl.cpp

@@ -442,6 +442,8 @@ struct GenELF64PluginTy final : public GenericPluginTy {
 #endif
 #elif defined(__riscv) && (__riscv_xlen == 64)
     return llvm::Triple::riscv64;
+#elif defined(__loongarch__) && (__loongarch_grlen == 64)
+    return llvm::Triple::loongarch64;
 #else
     return llvm::Triple::UnknownArch;
 #endif