Index: External/CMakeLists.txt
===================================================================
--- External/CMakeLists.txt
+++ External/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_subdirectory(CUDA)
+add_subdirectory(HIP)
 add_subdirectory(HMMER)
 add_subdirectory(Nurbs)
 add_subdirectory(Povray)
Index: External/CUDA/CMakeLists.txt
===================================================================
--- External/CUDA/CMakeLists.txt
+++ External/CUDA/CMakeLists.txt
@@ -1,4 +1,5 @@
 include(External)
+include(Variant)
 llvm_externals_find(TEST_SUITE_CUDA_ROOT "cuda" "CUDA prerequisites")
 
 set(SUPPORTED_GPU_CUDA_7_0
@@ -30,83 +31,36 @@
 set(SUPPORTED_GPU_CUDA_11_0 ${SUPPORTED_GPU_CUDA_10_2}
   sm_80)
 
-# Helper macro to extract version number at the end of the string
-# Input: get_version(Var String)
-#    Where String = /some/string/with/version-x.y.z
-# Output:
-#    Sets Var=x.y.z
-macro(get_version Var Path)
-    string(REGEX MATCH "[0-9]+(\\.[0-9]+)*$" ${Var} ${Path})
-endmacro (get_version)
-
-# Helper function to glob CUDA source files and set LANGUAGE property
-# to CXX on each of them. Sets Var in parent scope to the list of
-# files found.
-macro(cuda_glob Var)
-  file(GLOB FileList ${ARGN})
-  foreach(File IN LISTS FileList)
-    if(${File} MATCHES ".*\.cu$")
-      set_source_files_properties(${File} PROPERTIES LANGUAGE CXX)
-    endif()
-  endforeach()
-  set(${Var} ${FileList})
-endmacro(cuda_glob)
-
-macro(create_one_local_test_f Name FileGlob FilterRegex)
-  if (${VariantSuffix} MATCHES ${FilterRegex})
-    cuda_glob(_sources ${FileGlob})
-    set(_executable ${Name}-${VariantSuffix})
-    set(_executable_path ${CMAKE_CURRENT_BINARY_DIR}/${_executable})
-    llvm_test_run()
-    set(REFERENCE_OUTPUT)
-    # Verify reference output if it exists.
-    if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${Name}.reference_output)
-      set(REFERENCE_OUTPUT ${Name}.reference_output)
-      llvm_test_verify(WORKDIR ${CMAKE_CURRENT_BINARY_DIR}
-        ${FPCMP} %o ${REFERENCE_OUTPUT}-${VariantSuffix}
-      )
-      llvm_test_executable(${_executable} ${_sources})
-      llvm_test_data(${_executable}
-                     DEST_SUFFIX "-${VariantSuffix}"
-                     ${REFERENCE_OUTPUT})
-    else()
-      llvm_test_executable(${_executable} ${_sources})
-    endif()
-    target_compile_options(${_executable} PUBLIC ${VariantCPPFLAGS})
-    if(VariantLibs)
-      target_link_libraries(${_executable} ${VariantLibs})
-    endif()
-    add_dependencies(cuda-tests-simple-${VariantSuffix} ${_executable})
-    # Local tests are presumed to be fast.
-    list(APPEND CUDA_SIMPLE_TEST_TARGETS ${_executable}.test)
-  endif()
-endmacro()
-
-macro(create_one_local_test Name FileGlob)
-  create_one_local_test_f(${Name} ${FileGlob} ".*")
-endmacro()
-
 # Create targets for CUDA tests that are part of the test suite.
 macro(create_local_cuda_tests VariantSuffix)
-  create_one_local_test(assert assert.cu)
-  create_one_local_test(axpy axpy.cu)
-  create_one_local_test(algorithm algorithm.cu)
-  create_one_local_test(cmath cmath.cu)
-  create_one_local_test(complex complex.cu)
-  create_one_local_test(math_h math_h.cu)
-  create_one_local_test(new new.cu)
-  create_one_local_test(empty empty.cu)
-  create_one_local_test(printf printf.cu)
-  create_one_local_test(future future.cu)
-  create_one_local_test(builtin_var builtin_var.cu)
-  # We only need SIMD tests on CUDA-8.0 to verivy that our reference is correct
+  set(VariantOffload "cuda")
+  list(APPEND CUDA_LOCAL_TESTS assert)
+  list(APPEND CUDA_LOCAL_TESTS axpy)
+  list(APPEND CUDA_LOCAL_TESTS algorithm)
+  list(APPEND CUDA_LOCAL_TESTS cmath)
+  list(APPEND CUDA_LOCAL_TESTS complex)
+  list(APPEND CUDA_LOCAL_TESTS math_h)
+  list(APPEND CUDA_LOCAL_TESTS new)
+  list(APPEND CUDA_LOCAL_TESTS empty)
+  list(APPEND CUDA_LOCAL_TESTS printf)
+  list(APPEND CUDA_LOCAL_TESTS future)
+  list(APPEND CUDA_LOCAL_TESTS builtin_var)
+  list(APPEND CUDA_LOCAL_TESTS test_round)
+  foreach(_cuda_test IN LISTS CUDA_LOCAL_TESTS)
+    create_one_local_test(${_cuda_test} ${_cuda_test}.cu
+                          ${VariantOffload} ${VariantSuffix}
+                          "${VariantCPPFLAGS}" "${VariantLibs}")
+  endforeach()
+
+  # We only need SIMD tests on CUDA-8.0 to verify that our reference is correct
   # and matches NVIDIA-provided one.  and on CUDA-9.2 to verify that clang's
   # implementation matches the reference.  This test also happens to be the
   # longest one, so by not running unnecessary instances we speed up cuda
   # buildbot a lot.
   create_one_local_test_f(simd simd.cu
-                          "cuda-(8[.]0|9[.]2)-c[+][+]11-libc[+][+]")
-  create_one_local_test(test_round test_round.cu)
+                          "cuda-(8[.]0|9[.]2)-c[+][+]11-libc[+][+]"
+                          ${VariantOffload} ${VariantSuffix}
+                          "${VariantCPPFLAGS}" "${VariantLibs}")
 endmacro()
 
 macro(thrust_make_test_name TestName TestSourcePath)
@@ -196,7 +150,7 @@
   # Target for CUDA tests that take little time to build and run.
   add_custom_target(check-cuda-simple-${VariantSuffix}
     COMMAND ${TEST_SUITE_LIT} ${TEST_SUITE_LIT_FLAGS}
-            ${CUDA_SIMPLE_TEST_TARGETS}
+            ${VARIANT_SIMPLE_TEST_TARGETS}
     WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
     DEPENDS cuda-tests-simple-${VariantSuffix}
     USES_TERMINAL)
Index: External/HIP/CMakeLists.txt
===================================================================
--- /dev/null
+++ External/HIP/CMakeLists.txt
@@ -0,0 +1,98 @@
+include(External)
+include(Variant)
+llvm_externals_find(TEST_SUITE_HIP_ROOT "hip" "HIP prerequisites")
+
+# Create targets for HIP tests that are part of the test suite.
+macro(create_local_hip_tests VariantSuffix)
+  set(VariantOffload "hip")
+  # Add HIP tests to be added to hip-tests-simple
+  list(APPEND HIP_LOCAL_TESTS empty)
+  list(APPEND HIP_LOCAL_TESTS saxpy)
+  foreach(_hip_test IN LISTS HIP_LOCAL_TESTS)
+    create_one_local_test(${_hip_test} ${_hip_test}.hip
+                          ${VariantOffload} ${VariantSuffix}
+                          "${VariantCPPFLAGS}" "${VariantLibs}")
+  endforeach()
+endmacro()
+
+function(create_hip_test VariantSuffix)
+  message(STATUS "Creating HIP test variant ${VariantSuffix}")
+  add_custom_target(hip-tests-simple-${VariantSuffix}
+    COMMENT "Build HIP test variant ${VariantSuffix}")
+
+  set(VariantCPPFLAGS ${_HIP_CPPFLAGS})
+  set(VariantLibs ${_HIP_Libs})
+  list(APPEND LDFLAGS ${_HIP_LDFLAGS})
+
+  create_local_hip_tests(${VariantSuffix})
+  add_dependencies(hip-tests-simple hip-tests-simple-${VariantSuffix})
+
+  add_custom_target(check-hip-simple-${VariantSuffix}
+    COMMAND ${TEST_SUITE_LIT} ${TEST_SUITE_LIT_FLAGS}
+            ${VARIANT_SIMPLE_TEST_TARGETS}
+    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+    DEPENDS hip-tests-simple-${VariantSuffix}
+    USES_TERMINAL)
+  add_dependencies(check-hip-simple check-hip-simple-${VariantSuffix})
+endfunction(create_hip_test)
+
+macro(create_hip_tests)
+  # Find all rocm installations at Externals/hip/ directory.
+  # For ROCm, the path looks like rocm-4.1.0
+  message(STATUS "Checking HIP prerequisites in ${TEST_SUITE_HIP_ROOT}")
+  file(GLOB RocmVersions ${TEST_SUITE_HIP_ROOT}/rocm-*)
+  list(SORT RocmVersions)
+  foreach(RocmDir IN LISTS RocmVersions)
+    get_version(RocmVersion ${RocmDir})
+    message(STATUS "Found ROCm ${RocmVersion}")
+    list(APPEND ROCM_PATHS ${RocmDir})
+    add_library(amdhip64-${RocmVersion} SHARED IMPORTED)
+    set_property(TARGET amdhip64-${RocmVersion} PROPERTY IMPORTED_LOCATION
+      ${RocmDir}/lib/libamdhip64.so)
+  endforeach(RocmDir)
+
+  if(NOT ROCM_PATHS)
+    message(SEND_ERROR
+      "There are no ROCm installations in ${TEST_SUITE_HIP_ROOT}")
+    return()
+  endif()
+
+  add_custom_target(hip-tests-simple
+    COMMENT "Build all simple HIP tests")
+  add_custom_target(check-hip-simple
+    COMMENT "Run all simple HIP tests")
+
+  if(NOT AMDGPU_ARCHS)
+    list(APPEND AMDGPU_ARCHS "gfx906;gfx908")
+  endif()
+
+  foreach(_RocmPath ${ROCM_PATHS})
+    get_version(_RocmVersion ${_RocmPath})
+    set(_HIP_Suffix "hip-${_RocmVersion}")
+    # Set up HIP test flags
+    set(_HIP_CPPFLAGS -xhip --hip-device-lib-path=${_RocmPath}/amdgcn/bitcode
+                      -I${_RocmPath}/include)
+    set(_HIP_LDFLAGS -L${_RocmPath}/lib -lamdhip64)
+    set(_HIP_Libs amdhip64-${RocmVersion})
+
+    # Unset these for each iteration of rocm path.
+    set(_ArchFlags)
+    set(_ArchList)
+    foreach(_AMDGPUArch IN LISTS AMDGPU_ARCHS)
+      list(APPEND _ArchFlags --offload-arch=${_AMDGPUArch})
+    endforeach()
+    message(STATUS "Building ${_RocmPath} targets for ${AMDGPU_ARCHS}")
+    list(APPEND _HIP_CPPFLAGS ${_ArchFlags})
+
+    create_hip_test(${_HIP_Suffix})
+  endforeach()
+
+  add_custom_target(hip-tests-all DEPENDS hip-tests-simple
+    COMMENT "Build all HIP tests.")
+
+  file(COPY lit.local.cfg DESTINATION "${CMAKE_CURRENT_BINARY_DIR}")
+endmacro(create_hip_tests)
+
+if(TEST_SUITE_HIP_ROOT)
+  create_hip_tests()
+endif()
Index: External/HIP/README
===================================================================
--- /dev/null
+++ External/HIP/README
@@ -0,0 +1,30 @@
+HIP Tests
+==========
+
+HIP tests are enabled if cmake is invoked with
+-DTEST_SUITE_EXTERNALS_DIR=<externals path> and specified externals
+directory contains at least one ROCm installation.
+
+Expected externals directory structure:
+Externals/
+  hip/
+    rocm-X.Y.Z/ -- One or more ROCm installation.
+
+export EXTERNAL_DIR=/your/Externals/path
+export AMDGPU_ARCHS=gfx906;gfx908 # List of AMDGPU archs to compile
+export CLANG_DIR=/your/clang/build/dir
+export TEST_SUITE_DIR=/path/to/test-suite-sources
+
+Configure, build and run tests:
+
+```
+$ mkdir test-suite-build-dir
+$ cd test-suite-build-dir
+$ PATH=$CLANG_DIR/bin:$PATH CXX=clang++ CC=clang cmake -G Ninja -DTEST_SUITE_EXTERNALS_DIR=$EXTERNAL_DIR -DAMDGPU_ARCHS=$AMDGPU_ARCHS -DCMAKE_CXX_COMPILER="$CLANG_DIR/bin/clang++" -DCMAKE_C_COMPILER="$CLANG_DIR/bin/clang" $TEST_SUITE_DIR
+$ ninja hip-tests-simple
+$ ninja check-hip-simple
+```
+
+This will build every test for each of the installed ROCm in the
+$EXTERNAL_DIR/hip location, and run them against the expected
+reference_output.
Index: External/HIP/empty.hip
===================================================================
--- /dev/null
+++ External/HIP/empty.hip
@@ -0,0 +1 @@
+int main(int argc, char **argv) { return 0; }
Index: External/HIP/empty.reference_output
===================================================================
--- /dev/null
+++ External/HIP/empty.reference_output
@@ -0,0 +1 @@
+exit 0
Index: External/HIP/lit.local.cfg
===================================================================
--- /dev/null
+++ External/HIP/lit.local.cfg
@@ -0,0 +1,14 @@
+# -*- python -*-
+
+import os
+
+hip_env_vars = [
+    'HIP_VISIBLE_DEVICES',
+    'LD_LIBRARY_PATH',
+]
+
+for var in hip_env_vars:
+  if var in os.environ:
+    config.environment[var] = os.environ[var]
+
+config.traditional_output = True
Index: External/HIP/saxpy.hip
===================================================================
--- /dev/null
+++ External/HIP/saxpy.hip
@@ -0,0 +1,62 @@
+#include <iostream>
+
+#include <hip/hip_runtime.h>
+
+#define N  (1024 * 500)
+
+__global__ void saxpy(float a, float* x, float* y) {
+    size_t tid = blockIdx.x * blockDim.x + threadIdx.x;
+    if (tid < N) y[tid] = a * x[tid] + y[tid];
+}
+
+int main() {
+
+  const float a = 100.0f;
+  float* x = (float*)malloc(N * sizeof(float));
+  float* y = (float*)malloc(N * sizeof(float));
+
+  // Initialize the input data.
+  for (size_t i = 0; i < N; ++i) {
+    x[i] = static_cast<float>(i);
+    y[i] = static_cast<float>(i * 2);
+  }
+
+  // Make a copy for the GPU implementation.
+  float* d_x;
+  float* d_y;
+  hipMalloc((void**)&d_x, N * sizeof(float));
+  hipMalloc((void**)&d_y, N * sizeof(float));
+  hipMemcpy(d_x, x, N * sizeof(float), hipMemcpyHostToDevice);
+  hipMemcpy(d_y, y, N * sizeof(float), hipMemcpyHostToDevice);
+
+  // CPU implementation of saxpy.
+  for (int i = 0; i < N; i++) {
+    y[i] = a * x[i] + y[i];
+  }
+
+  // Launch a GPU kernel to compute the saxpy.
+  saxpy<<<(N+255)/256, 256>>>(a, d_x, d_y);
+
+  // Copy the device results to host.
+  float* h_y = (float*)malloc(N * sizeof(float));
+  hipDeviceSynchronize();
+  hipMemcpy(h_y, d_y, N * sizeof(float), hipMemcpyDeviceToHost);
+
+  // Verify the results match CPU.
+  int errors = 0;
+  for (int i = 0; i < N; i++) {
+    if (fabs(y[i] - h_y[i]) > fabs(y[i] * 0.0001f))
+      errors++;
+  }
+  if (errors != 0)
+    std::cout << errors << " errors" << std::endl;
+  else
+    std::cout << "PASSED!" << std::endl;
+
+  free(h_y);
+  free(x);
+  free(y);
+  hipFree(d_x);
+  hipFree(d_y);
+  return errors;
+}
Index: External/HIP/saxpy.reference_output
===================================================================
--- /dev/null
+++ External/HIP/saxpy.reference_output
@@ -0,0 +1,2 @@
+PASSED!
+exit 0
Index: cmake/modules/Variant.cmake
===================================================================
--- /dev/null
+++ cmake/modules/Variant.cmake
@@ -0,0 +1,72 @@
+include(External)
+
+# Helper macro to extract version number at the end of the string
+# Input: get_version(Var String)
+#    Where String = /some/string/with/version-x.y.z
+# Output:
+#    Sets Var=x.y.z
+macro(get_version Var Path)
+    string(REGEX MATCH "[0-9]+(\\.[0-9]+)*$" ${Var} ${Path})
+endmacro (get_version)
+
+# Helper function to glob CUDA source files and set LANGUAGE property
+# to CXX on each of them. Sets Var in parent scope to the list of
+# files found.
+macro(gpu_glob Var)
+  file(GLOB FileList ${ARGN})
+  foreach(File IN LISTS FileList)
+    if(${File} MATCHES ".*\.cu$" OR ${File} MATCHES ".*\.hip$")
+      set_source_files_properties(${File} PROPERTIES LANGUAGE CXX)
+    endif()
+  endforeach()
+  set(${Var} ${FileList})
+endmacro(gpu_glob)
+
+macro(create_one_local_test_f Name FileGlob FilterRegex
+                              VariantOffload VariantSuffix
+                              VariantCPPFLAGS VariantLibs)
+  if (${VariantSuffix} MATCHES ${FilterRegex})
+    gpu_glob(_sources ${FileGlob})
+    set(_executable ${Name}-${VariantSuffix})
+    set(_executable_path ${CMAKE_CURRENT_BINARY_DIR}/${_executable})
+    llvm_test_run()
+    set(REFERENCE_OUTPUT)
+    # Verify reference output if it exists.
+    if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${Name}.reference_output)
+      set(REFERENCE_OUTPUT ${Name}.reference_output)
+      llvm_test_verify(WORKDIR ${CMAKE_CURRENT_BINARY_DIR}
+        ${FPCMP} %o ${REFERENCE_OUTPUT}-${VariantSuffix}
+      )
+      llvm_test_executable(${_executable} ${_sources})
+      llvm_test_data(${_executable}
+                     DEST_SUFFIX "-${VariantSuffix}"
+                     ${REFERENCE_OUTPUT})
+    else()
+      llvm_test_executable(${_executable} ${_sources})
+    endif()
+    target_compile_options(${_executable} PUBLIC ${VariantCPPFLAGS})
+    if(VariantLibs)
+      target_link_libraries(${_executable} ${VariantLibs})
+    endif()
+    if (${VariantOffload} MATCHES "hip")
+      add_dependencies(hip-tests-simple-${VariantSuffix} ${_executable})
+    else()
+      add_dependencies(cuda-tests-simple-${VariantSuffix} ${_executable})
+    endif()
+    # Local tests are presumed to be fast.
+    list(APPEND VARIANT_SIMPLE_TEST_TARGETS ${_executable}.test)
+  endif()
+endmacro()
+
+# Helper macro to create a local test for a VariantSuffix.
+# Inputs: Name, File, Offload, Suffix, CPPFLAGS, Libs
+# Output: Dependencies added for <cuda||hip>-tests-simple-<suffix>,
+#         and VARIANT_SIMPLE_TEST_TARGETS created.
+macro(create_one_local_test Name FileGlob
+                            VariantOffload VariantSuffix
+                            VariantCPPFLAGS VariantLibs)
+  create_one_local_test_f(${Name} ${FileGlob} ".*"
+                          ${VariantOffload} ${VariantSuffix}
+                          "${VariantCPPFLAGS}" "${VariantLibs}")
+endmacro()
+