Even if the compiler supports an "alternate" short float type (e.g.,
_Float16), check to make sure that the compiler will correctly link
applications that perform mathematical operations on that type.
Carefully choose the mathematical test in the configure check to
ensure the mathematical operation is not removed by compiler
optimization (when setting CFLAGS=-O1 or higher).
Out of the box, clang 6.0.x and 7.0.x will fail to link applications
that try to perform addition (and other mathematical operations) on
_Float16 variables (an additional CLI flag is required to enable
software emulation of _Float16). If we detect a situation where the
type is supported by a sample program fails to link and the basename
of $CC is "clang", emit a warning and point the user to a relevant
README.
Signed-off-by: Jeff Squyres <jsquyres@cisco.com>
Signed-off-by: KAWASHIMA Takahiro <t-kawashima@fujitsu.com>
In order to work around an issue with flang based compilers,
avoid declaring bind(C) constants and use plain Fortran parameter
instead.
For example,
type(MPI_Comm), bind(C, name="ompi_f08_mpi_comm_world") OMPI_PROTECTED :: MPI_COMM_WORLD
is changed to
type(MPI_Comm), parameter :: MPI_COMM_WORLD = MPI_Comm(OMPI_MPI_COMM_WORLD)
Note that in order to preserve ABI compatibility, ompi/mpi/fortran/use-mpi-f08/constants.{c,h}
have been kept even if its symbols are no more referenced by Open MPI.
Refs. open-mpi/ompi#7091
Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>
the shortfloat extension is only made of header files,
and hence do not require a library to be built.
Refs. open-mpi/ompi#6205
Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>
Signed-off-by: KAWASHIMA Takahiro <t-kawashima@jp.fujitsu.com>
`MPIX_C_FLOAT16` is defined as a synonym for `MPIX_SHORT_FLOAT`
if the C compiler supports `_Float16`, which is defined in
ISO/IEC JTC 1/SC 22/WG 14 N1945 (ISO/IEC TS 18661-3:2015).
This name and meaning are same as that of MPICH. This may be
a transitional datatype until the MPI Forum decides a proper
name for the type.
Signed-off-by: KAWASHIMA Takahiro <t-kawashima@jp.fujitsu.com>
This extension provides additional MPI datatypes `MPIX_SHORT_FLOAT`,
`MPIX_C_SHORT_FLOAT_COMPLEX`, and `MPIX_CXX_SHORT_FLOAT_COMPLEX`
for `short float` (C/C++), `short float _Complex` (C), and
`std::complex<short float>` (C++), respectively, or their alternate
types like `_Float16`.
See `ompi/mpiext/shortfloat/README.txt` for details.
Signed-off-by: KAWASHIMA Takahiro <t-kawashima@jp.fujitsu.com>
