diff --git a/External/SPEC/CFP2017speed/628.pop2_s/CMakeLists.txt b/External/SPEC/CFP2017speed/628.pop2_s/CMakeLists.txt
new file mode 100644
--- /dev/null
+++ b/External/SPEC/CFP2017speed/628.pop2_s/CMakeLists.txt
@@ -0,0 +1,164 @@
+# https://www.spec.org/cpu2017/Docs/benchmarks/628.pop2_s.html
+include(../../SpecCPU2017.cmake)
+if (NOT TEST_SUITE_SPEC2017_ROOT)
+  return ()
+endif ()
+
+ninja_required()
+
+speccpu2017_benchmark(SPEED)
+
+# Check if compiler can support big-endian IO format, if true proceed
+# otherwise, return immediately. This is due to some binary input
+# files stored in big-endian format
+if (ENDIAN STREQUAL "little")
+  # GCC
+  check_fortran_compiler_flag("-fconvert=big-endian" SUPPORTS_FCONVERT_BIG_ENDIAN)
+  # Intel
+  check_fortran_compiler_flag("-convert big_endian" SUPPORTS_CONVERT_BIG_ENDIAN)
+  # Flang
+  # TBD
+  if (NOT SUPPORTS_FCONVERT_BIG_ENDIAN)
+  elseif (NOT SUPPORTS_CONVERT_BIG_ENDIAN)
+  else ()
+    message(WARN "628.pop2_s not supported. No way to read big-endian binary IO on little-endian architecture.")
+    return ()
+  endif ()
+endif ()
+
+macro(pop2_prepare_rundir)
+  # Re-use the speccpu2017_prepare_rundir but then implement an input
+  # file fix at the end. input file for pop2 is hard-coded to drv_in,
+  # but actual filename in SPEC2017 benchmark input directory is
+  # drv_in.in. The SPEC perl run script renames the file as well.
+  speccpu2017_prepare_rundir()
+  foreach (_runtype IN LISTS TEST_SUITE_RUN_TYPE)
+    llvm_copy(${PROG} "${RUN_${_runtype}_DIR}/drv_in" "${INPUT_${_runtype}_DIR}/drv_in.in")
+  endforeach ()
+endmacro()
+
+speccpu2017_add_include_dirs(
+  ${CMAKE_CURRENT_BINARY_DIR}
+  ${SRC_DIR}
+  ${SRC_DIR}/netcdf/include
+)
+
+# pop2 has Fortran sources that need to be processed with specpp and C
+# sources that do not require it.
+
+# Compiler definitions affect C and *.f90 files, but not *.F90 files.
+add_definitions(
+  -D_MPISERIAL
+  -D_NETCDF
+  -D_USEBOX
+  -DCCSMCOUPLED=1
+  -DNO_SHR_VMATH
+  -DBLCKX=50
+  -DBLCKY=4
+  -DMXBLCKS=58
+  -DNO_GETTIMEOFDAY
+  -DSPEC_CASE_FLAG
+)
+
+
+## test ########################################################################
+
+speccpu2017_run_test(RUN_TYPE test)
+
+## train #######################################################################
+
+speccpu2017_run_test(RUN_TYPE train)
+
+## ref #########################################################################
+
+speccpu2017_run_test(RUN_TYPE ref)
+
+################################################################################
+
+# SPEC Test has both absolute and relative tolerance with same order
+speccpu2017_verify_output(IGNORE_WHITESPACE ABSOLUTE_TOLERANCE 0.03 RELATIVE_TOLERANCE 0.03)
+
+# *.F90 files are preprocessed with specpp and written to the CMake build
+# directory. We only list C sources files and Fortran files that don't
+# need to be preprocessed below.
+speccpu2017_add_executable(
+  netcdf/attr.c
+  netcdf/dim.c
+  netcdf/error.c
+  netcdf/fort-attio.c
+  netcdf/fort-control.c
+  netcdf/fort-dim.c
+  netcdf/fort-genatt.c
+  netcdf/fort-geninq.c
+  netcdf/fort-genvar.c
+  netcdf/fort-lib.c
+  netcdf/fort-misc.c
+  netcdf/fort-v2compat.c
+  netcdf/fort-var1io.c
+  netcdf/fort-varaio.c
+  netcdf/fort-vario.c
+  netcdf/fort-varmio.c
+  netcdf/fort-varsio.c
+  netcdf/libvers.c
+  netcdf/nc.c
+  netcdf/ncx.c
+  netcdf/posixio.c
+  netcdf/putget.c
+  netcdf/string.c
+  netcdf/v1hpg.c
+  netcdf/v2i.c
+  netcdf/var.c
+  netcdf/netcdf.f90
+  netcdf/typeSizes.f90
+  mpi.c
+  send.c
+  recv.c
+  collective.c
+  req.c
+  list.c
+  handles.c
+  comm.c
+  group.c
+  time.c
+  pack.c
+  get_zeits.c
+  pnetcdfversion.c
+  topology.c
+  f_wrappers.c
+  GPTLget_memusage.c
+  GPTLprint_memusage.c
+  GPTLutil.c
+  shr_jlcp.c
+  shr_vmath_fwrap.c
+  threadutil.c
+)
+
+# Preprocess *.F90 with specpp and add sources to target
+speccpu2017_run_specpp(
+  -D_MPISERIAL
+  -D_NETCDF
+  -D_USEBOX
+  -DCCSMCOUPLED=1
+  -DNO_SHR_VMATH
+  -DBLCKX=50
+  -DBLCKY=4
+  -DMXBLCKS=58
+  -DNO_GETTIMEOFDAY
+  -I${SRC_DIR}/netcdf/include
+)
+
+
+# Several compiler options below for C and Fortran
+set_property(TARGET ${PROG} PROPERTY C_STANDARD 99)
+
+if (SUPPORTS_FALLOW_ARGUMENT_MISMATCH)
+  target_compile_options(${PROG} PRIVATE $<$<COMPILE_LANGUAGE:Fortran>:-fallow-argument-mismatch>)
+endif ()
+
+if (SUPPORTS_FCONVERT_BIG_ENDIAN) # GCC
+  target_compile_options(${PROG} PRIVATE -fconvert=big-endian)
+elseif (SUPPORTS_CONVERT_BIG_ENDIAN) # Intel
+  target_compile_options(${PROG} PRIVATE -convert big_endian)
+endif ()
+
+pop2_prepare_rundir()
diff --git a/External/SPEC/CFP2017speed/CMakeLists.txt b/External/SPEC/CFP2017speed/CMakeLists.txt
--- a/External/SPEC/CFP2017speed/CMakeLists.txt
+++ b/External/SPEC/CFP2017speed/CMakeLists.txt
@@ -6,7 +6,7 @@
 if (TEST_SUITE_FORTRAN)
   #add_subdirectory(621.wrf_s)     # Fortran, C
   add_subdirectory(627.cam4_s)     # Fortran, C
-  #add_subdirectory(628.pop2_s)    # Fortran, C
+  add_subdirectory(628.pop2_s)     # Fortran, C
 endif ()
 add_subdirectory(638.imagick_s)    # C
 add_subdirectory(644.nab_s)        # C
diff --git a/External/SPEC/SpecCPU2017.cmake b/External/SPEC/SpecCPU2017.cmake
--- a/External/SPEC/SpecCPU2017.cmake
+++ b/External/SPEC/SpecCPU2017.cmake
@@ -115,23 +115,31 @@
     endif ()
 
     # Portability flags
+    # SPEC_AUTO_BYTEORDER_value variable is used for Fortran tests that use specpp
     if (ENDIAN STREQUAL "little")
       add_definitions(-DSPEC_AUTO_BYTEORDER=0x12345678)
+      set(SPEC_AUTO_BYTEORDER_VALUE 0x12345678)
     elseif (ENDIAN STREQUAL "big")
       add_definitions(-DSPEC_AUTO_BYTEORDER=0x87654321)
+      set(SPEC_AUTO_BTYEORDER_VALUE 0x87654321)
     endif ()
 
     check_type_size("long long" SIZEOF_LONG_LONG)
     check_type_size("long" SIZEOF_LONG)
     check_type_size("int" SIZEOF_INT)
+    # SPEC_PTR_TYPE variable is used for Fortran tests that use specpp
     if (CMAKE_SIZEOF_VOID_P EQUAL 4 AND SIZEOF_LONG_LONG EQUAL 8 AND SIZEOF_LONG EQUAL 4 AND SIZEOF_INT EQUAL 4)
       add_definitions(-DSPEC_ILP32)
+      set(SPEC_PTR_TYPE ILP32)
     elseif (CMAKE_SIZEOF_VOID_P EQUAL 8 AND SIZEOF_LONG_LONG EQUAL 8 AND SIZEOF_LONG EQUAL 4 AND SIZEOF_INT EQUAL 4)
       add_definitions(-DSPEC_P64)
+      set(SPEC_PTR_TYPE P64)
     elseif (CMAKE_SIZEOF_VOID_P EQUAL 8 AND SIZEOF_LONG_LONG EQUAL 8 AND SIZEOF_LONG EQUAL 8 AND SIZEOF_INT EQUAL 4)
       add_definitions(-DSPEC_LP64)
+      set(SPEC_PTR_TYPE LP64)
     elseif (CMAKE_SIZEOF_VOID_P EQUAL 8 AND SIZEOF_LONG_LONG EQUAL 8 AND SIZEOF_LONG EQUAL 8 AND SIZEOF_INT EQUAL 8)
       add_definitions(-DSPEC_ILP64)
+      set(SPEC_PTR_TYPE ILP64)
     else ()
       message(FATAL_ERROR "SPEC CPU 2017 unsupported data model (supported: ILP32/LLP64/LP64/ILP64)")
     endif ()
@@ -166,6 +174,10 @@
     # No OpenMP for the moment, even for the _s suites.
     add_definitions(-DSPEC_SUPPRESS_OPENMP)
 
+    # Used by cam4, pop2, and wrf tests for portability
+    # https://gcc.gnu.org/gcc-10/porting_to.html
+    check_fortran_compiler_flag("-fallow-argument-mismatch" SUPPORTS_FALLOW_ARGUMENT_MISMATCH)
+
   endif ()
 endmacro()
 
@@ -351,3 +363,38 @@
     llvm_copy_dir(${PROG} "${RUN_${_runtype}_DIR}" "${INPUT_${_runtype}_DIR}")
   endforeach ()
 endmacro()
+
+# Run specpp on all Fortran files, but do not do it recursively.
+# https://www.spec.org/cpu2017/Docs/specpp.html
+# specpp is needed due to legacy use of filepp by climate/weather codes.
+macro(speccpu2017_run_specpp)
+  set(_specpp_bin ${TEST_SUITE_SPEC2017_ROOT}/bin/specpp)
+  # We don't use GLOB_RECURSE below because only the *.F90 files in the top
+  # level directory needs to be processed by specpp.
+  file(GLOB _specpp_sources ${SRC_DIR}/*.F90)
+  list(REMOVE_ITEM _specpp_sources ${SRC_DIR}/test.F90) # pop2 source file that doesn't get linked
+
+  # Add common specpp arguments used by all SPEC CPU 2017 tests.
+  # -U__FILE__ is included as a work around. Source files uses _FILE_
+  # as the filename without the path, but a few source files have a
+  # typo and use __FILE__ instead which is an absolute path. So specpp
+  # fails to do a replacement with just the filename (i.e. without the
+  # path as intended). This is usually a benign error, but __FILE__
+  # can lead to a deeply nested directory due CMake's build
+  # directories. As a result, the source file line length becomes
+  # incredibly long, so you end up with a ridiculously long line that
+  # some compilers, like GCC, are unable to compile.
+  set(ARG_COMMON -w -U__FILE__ -DSPEC -DSPEC_CPU -DNDEBUG -DSPEC_CASE_FLAG
+    -DSPEC_AUTO_BYTEORDER=${SPEC_AUTO_BYTEORDER_VALUE} -DSPEC_${SPEC_PTR_TYPE} -DSPEC_SUPPRESS_OPENMP -I${SRC_DIR})
+
+  foreach(_absfilename ${_specpp_sources})
+    get_filename_component(_filename ${_absfilename} NAME)
+    add_custom_command(
+      OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${_filename}"
+      COMMAND "${_specpp_bin}" ${ARG_COMMON} ${ARGN} "${_absfilename}" > "${CMAKE_CURRENT_BINARY_DIR}/${_filename}"
+      DEPENDS "${_absfilename}"
+      VERBATIM
+      )
+    target_sources(${PROG} PRIVATE "${CMAKE_CURRENT_BINARY_DIR}/${_filename}")
+  endforeach ()
+endmacro()