Draft: Fortran Support

Testing using level 2

Disqualified Tests:

• Passing NULL/MPI_REQUEST_NULL causes compile errors in Fortran, disqualifying InvalidParam tests that do this
  • Disqualifies 17 tests (lvl1) / 136 (lvl2)
• A lot of tests are currently removed due to datatypes, i.e., MPI C types that do not exist / are not implemented yet for Fortran
  • No effect on lvl1, as only MPI_INT and MPI_DOUBLE are used / 501 disqualified (lvl2)

Unfixable, but not disqualified:

• InvalidParam-Status-mpi_recv-002: MPI_STATUSES_IGNORE rejected by compiler, different rank than expected
  • Error class does not exist for Fortran. Disqualifies 1 test (lvl1) / 16 (lvl2)

MPI Issues:

• https://github.com/open-mpi/ompi/issues/9534 - Causes issues with Precv_Init / Psend_init. Need recent OpenMPI version to avoid this
• https://github.com/open-mpi/ompi/pull/13308 - Bug in OpenMPI-git causes compilation failure as well

Types are translated from C to Fortran where applicable, though currently only for MPI_INT -> MPI_INTEGER, MPI_DOUBLE -> MPI_DOUBLE_PRECISION, MPI_C_BOOL -> MPI_LOGICAL as most Fortran MPI types are optional. Tests are formatted using fprettify (available from pip, added to Pipfile).

Common Issues encountered:

• MPI does not differentiate between bool and int, but does between integer and logical.
  • Workaround: Use bool where applicable in C code, then translate to logical
• Different integer size expectations cause compilation failures (no automatic extension)
  • Workaround: During parsing of apis.json, save the integer width, and perform explicit widening if needed.
• C usage of address-of-integer as a one-dimensional array does not work in Fortran
  • Workaround: Replace uses thereof with proper arrays
• Array Indexing starts at 1
  • Workaround: Implement explicit indexing to match C

MPI-BugBench bugs (since remembering to write them down):

• Deadlock in CallOrdering-mpi_improbe-mpi_send-001, wrong parameter used as flag
  • Note: Deadlock also happens in InvalidParam-flag-mpi_iprobe-002, but intended? (not_allocated flag is not waited on, but the "normal" one)

scripts/Infrastructure/MPICall.py

@@ -13,13 +13,13 @@ call_template_fort = "call @FUNC@(@ARGS@)"
 call_template_c    = "@FUNC@(@ARGS@);"
 
 
-def get_arg_str(args: typing.OrderedDict[str, str], bigint: typing.List[str] = []):
+def get_arg_str(args: typing.OrderedDict[str, str], bigint: typing.Dict[str,str] = {}):
     s = ""
     for k, v in args.items():
         assert v is not None
         v = adjust_var_language(v)
         if infvars.generator_language == "fort" and k in bigint:
-            v = f"int({v}, mpi_address_kind)"
+            v = f"int({v}, {bigint[k]})"
         s += str(v)
         s += ", "
     s = s[:-2]  # remove last ", "
@@ -30,7 +30,7 @@ class MPICall(Instruction):
 
     @override
     def __init__(self, function: str, args: typing.OrderedDict[str, str], version: str, rank: str | int = 'all',
-                 identifier: str = None, bigints: typing.List[str] = []):
+                 identifier: str = None, bigints: typing.Dict[str,str] = {}):
         super().__init__("", rank, identifier)
         self._function = function
         self._args = args